Add initial CRI support

cri-o was used as an example as it is relatively easy to setup a cluster
using that container runtime as compared to others.

When the probe.cri is enabled the CRI probe will be used to gather
the container information via the CRI API. For now only the basic
information is included in the generated report, those that we can get
via the CRI ListContainersRequest.

The cri make target generates the api.pb.go files by first fetching the
latest proto files from upstream and uses protoc to generate them.

Fix WithLatests() fixup on duplicate keys

The fixup() method was modifying a copy of its input, so you could get
duplicate keys in the output. Change it to return the new slice.

Thankfully this is rare: in most cases WithLatests() is called with
fields that are not duplicates of existing ones.

Fix ugorji/go's version

Not sure what happened, but `gvt` is most likely buggy.
Indeed, if you try to remove `ugorji/go/codec` and pull it again, with the revision listed in `vendor/manifest`, i.e.:
```
$ gvt delete github.com/ugorji/go/codec
$ gvt fetch --revision c062049c1793b01a3cc3fe786108edabbaf7756b github.com/ugorji/go/codec
YYYY/MM/DD HH:mm:SS Fetching: github.com/ugorji/go/codec
```
you then get the below build errors:
```
report/latest_map_generated.go:245:27: r.DecodeStringAsBytes undefined (type codec.decDriver has no field or method DecodeStringAsBytes)
report/latest_map_generated.go:497:27: r.DecodeStringAsBytes undefined (type codec.decDriver has no field or method DecodeStringAsBytes)
report/map_helpers.go:114:27: r.DecodeStringAsBytes undefined (type codec.decDriver has no field or method DecodeStringAsBytes)
report/report.codecgen.go:191:14: r.DecodeStringAsBytes undefined (type codec.decDriver has no field or method DecodeStringAsBytes)
report/report.codecgen.go:496:14: r.DecodeStringAsBytes undefined (type codec.decDriver has no field or method DecodeStringAsBytes)
report/report.codecgen.go:803:14: r.DecodeStringAsBytes undefined (type codec.decDriver has no field or method DecodeStringAsBytes)
report/report.codecgen.go:1001:14: r.DecodeStringAsBytes undefined (type codec.decDriver has no field or method DecodeStringAsBytes)
report/report.codecgen.go:1240:14: r.DecodeStringAsBytes undefined (type codec.decDriver has no field or method DecodeStringAsBytes)
report/report.codecgen.go:1567:14: r.DecodeStringAsBytes undefined (type codec.decDriver has no field or method DecodeStringAsBytes)
report/report.codecgen.go:1858:14: r.DecodeStringAsBytes undefined (type codec.decDriver has no field or method DecodeStringAsBytes)
report/report.codecgen.go:1858:14: too many errors
Makefile:104: recipe for target 'render/detailed/detailed.codecgen.go' failed
```
which I also got in another project importing Scope.

This is fixed by running the following:
```
$ gvt delete github.com/ugorji/go/codec
$ gvt fetch --revision 54210f4e076c57f351166f0ed60e67d3fca57a36 github.com/ugorji/go/codec
YYYY/MM/DD HH:mm:SS Fetching: github.com/ugorji/go/codec
```
Note that this revision was found in previous commit messages:
```
$ git log -S ugorji
[...]
commit 42bf0ded
Author: Bryan Boreham <bjboreham@gmail.com>
Date:   Sat Sep 23 21:08:33 2017 +0000

    Update ugorji/go/codec to latest commit 54210f4e076c57f351166f0ed60e67d3fca57a36

[...]
```

Pass a logger to middleware.Log

Should fix:
```
2018/07/23 20:29:49 http: panic serving 10.244.204.241:34716: runtime error: invalid memory address or nil pointer dereference
goroutine 1169 [running]:
net/http.(*conn).serve.func1(0xc420739a40)
/usr/local/go/src/net/http/server.go:1726 +0xd0
panic(0x17d5200, 0x2a7f5e0)
/usr/local/go/src/runtime/panic.go:502 +0x229
github.com/weaveworks/scope/vendor/github.com/weaveworks/common/middleware.Log.Wrap.func1(0x1dc60e0, 0xc4215e7a40, 0xc4202cee00)
/go/src/github.com/weaveworks/scope/vendor/github.com/weaveworks/common/middleware/logging.go:40 +0x3c7
[...]
```

Update from Sirupsen/logrus to sirupsen/logrus

This file appears when building under macOS

Fixes:
```
not enough arguments in call to signals.SignalHandlerLoop
	have ()
	want (logging.Interface, ...signals.SignalReceiver)
```

This fixes:
```
prog/app.go:310:2: undefined: "github.com/weaveworks/scope/vendor/github.com/weaveworks/weave/common".SignalHandlerLoop
prog/probe.go:309:2: undefined: "github.com/weaveworks/scope/vendor/github.com/weaveworks/weave/common".SignalHandlerLoop
```

```
$ rm -fr vendor/github.com/weaveworks/weave/vendor/github.com/sirupsen
```
fixed:
```
	"github.com/weaveworks/scope/vendor/github.com/weaveworks/weave/vendor/github.com/sirupsen/logrus".Formatter does not implement "github.com/weaveworks/scope/vendor/github.com/sirupsen/logrus".Formatter (wrong type for Format method)
		have Format(*"github.com/weaveworks/scope/vendor/github.com/weaveworks/weave/vendor/github.com/sirupsen/logrus".Entry) ([]byte, error)
		want Format(*"github.com/weaveworks/scope/vendor/github.com/sirupsen/logrus".Entry) ([]byte, error)
```

```
$ gvt delete github.com/weaveworks/weave/vendor/github.com/gogo/protobuf/proto
$ gvt delete github.com/docker/docker/vendor/github.com/gogo/protobuf/proto
$ gvt delete github.com/gogo/protobuf/gogoproto
$ gvt delete github.com/gogo/protobuf/proto
$ gvt delete github.com/gogo/protobuf/protoc-gen-gogo/descriptor
$ gvt delete github.com/gogo/protobuf/sortkeys
$ gvt delete github.com/gogo/protobuf/types
$ gvt delete google.golang.org/genproto/googleapis/rpc/status
$ gvt delete github.com/golang/protobuf/jsonpb
$ gvt delete github.com/golang/protobuf/proto
$ gvt delete github.com/golang/protobuf/protoc-gen-go/descriptor
$ gvt delete github.com/golang/protobuf/ptypes
$ gvt delete github.com/matttproud/golang_protobuf_extensions/pbutil
$ gvt fetch github.com/gogo/protobuf/proto
2018/07/23 18:33:10 Fetching: github.com/gogo/protobuf/proto
2018/07/23 18:33:15 · Fetching recursive dependency: github.com/gogo/protobuf/types
2018/07/23 18:33:15 ·· Fetching recursive dependency: github.com/gogo/protobuf/sortkeys
$ gvt fetch github.com/golang/protobuf/proto
2018/07/23 18:33:16 Fetching: github.com/golang/protobuf/proto
2018/07/23 18:33:19 · Fetching recursive dependency: github.com/golang/protobuf/ptypes/any
$ gvt fetch github.com/golang/protobuf/ptypes
2018/07/23 18:33:19 Fetching: github.com/golang/protobuf/ptypes
2018/07/23 18:33:19  Deleting existing subpackage to prevent overlap: github.com/golang/protobuf/ptypes/any
2018/07/23 18:33:22 · Skipping (existing): github.com/golang/protobuf/proto
$ gvt fetch github.com/matttproud/golang_protobuf_extensions/pbutil
2018/07/23 18:33:23 Fetching: github.com/matttproud/golang_protobuf_extensions/pbutil
2018/07/23 18:33:25 · Skipping (existing): github.com/golang/protobuf/proto
$ gvt fetch google.golang.org/genproto/googleapis/rpc/status
2018/07/23 18:33:25 Fetching: google.golang.org/genproto/googleapis/rpc/status
2018/07/23 18:33:31 · Skipping (existing): github.com/golang/protobuf/proto
2018/07/23 18:33:31 · Skipping (existing): github.com/golang/protobuf/ptypes/any
```
fixed:
```
vendor/google.golang.org/genproto/googleapis/rpc/status/status.pb.go:111:28: undefined: proto.InternalMessageInfo
```

```
$ gvt delete golang.org/x/net/context
$ gvt fetch golang.org/x/net/context
2018/07/23 18:03:49 Fetching: golang.org/x/net/context
$ git grep -l "golang.org/x/net/context" | grep -v vendor | xargs sed -i '' 's:golang.org/x/net/context:context:g'
$ git grep -l "context/ctxhttp" | grep -v vendor | xargs sed -i '' 's:context/ctxhttp:golang.org/x/net/context/ctxhttp:g'
$ gofmt -s -w app
$ gofmt -s -w common
$ gofmt -s -w probe
$ gofmt -s -w prog
$ gofmt -s -w tools
```
fixed a bunch of:
```
cannot use func literal (type func("github.com/weaveworks/scope/vendor/golang.org/x/net/context".Context) error) as type func("context".Context) error
```

```
$ gvt delete github.com/weaveworks/promrus
$ gvt fetch --tag v1.2.0 github.com/weaveworks/promrus
2018/07/23 17:46:59 Fetching: github.com/weaveworks/promrus
2018/07/23 17:47:03 · Skipping (existing): golang.org/x/net/context/ctxhttp
2018/07/23 17:47:03 · Skipping (existing): github.com/go-kit/kit/log
2018/07/23 17:47:03 · Skipping (existing): github.com/julienschmidt/httprouter
2018/07/23 17:47:03 · Skipping (existing): github.com/go-kit/kit/log/level
2018/07/23 17:47:03 · Skipping (existing): github.com/pkg/errors
2018/07/23 17:47:03 · Skipping (existing): gopkg.in/yaml.v2
2018/07/23 17:47:03 · Skipping (existing): gopkg.in/alecthomas/kingpin.v2
2018/07/23 17:47:03 · Skipping (existing): golang.org/x/net/context
2018/07/23 17:47:03 · Skipping (existing): github.com/stretchr/objx
$ rm -fr vendor/github.com/weaveworks/promrus/vendor/github.com/sirupsen/
```
switched from a "legacy" version of `promrus` to a regular one, and fixed:
```
	*promrus.PrometheusHook does not implement "github.com/weaveworks/scope/vendor/github.com/sirupsen/logrus".Hook (wrong type for Fire method)
		have Fire(*"github.com/weaveworks/scope/vendor/github.com/weaveworks/promrus/vendor/github.com/sirupsen/logrus".Entry) error
		want Fire(*"github.com/weaveworks/scope/vendor/github.com/sirupsen/logrus".Entry) error
```

For some reason, `Sirupsen/logrus` was still in `emicklei/go-restful-openapi`:
```
$ git grep Sirupsen
vendor/github.com/emicklei/go-restful-openapi/examples/security/api.go: "github.com/Sirupsen/logrus"
```
After running:
```
$ gvt delete github.com/emicklei/go-restful-openapi
$ gvt delete github.com/marccarre/go-restful-openapi
$ gvt fetch --revision 129557de7d9f2d2ca4a90cd31c379db90a561ad8 --branch lowercase-sirupsen github.com/marccarre/go-restful-openapi
2018/07/23 17:28:40 Fetching: github.com/marccarre/go-restful-openapi
2018/07/23 17:28:42 · Fetching recursive dependency: github.com/emicklei/go-restful-openapi
2018/07/23 17:28:44 ·· Skipping (existing): github.com/go-openapi/spec
2018/07/23 17:28:44 ·· Skipping (existing): github.com/emicklei/go-restful
2018/07/23 17:28:44 ·· Fetching recursive dependency: github.com/Sirupsen/logrus
2018/07/23 17:28:46 ··· Skipping (existing): github.com/sirupsen/logrus
2018/07/23 17:28:46 ··· Skipping (existing): golang.org/x/crypto/ssh/terminal
2018/07/23 17:28:46 ··· Skipping (existing): golang.org/x/sys/unix
2018/07/23 17:28:46 · Skipping (existing): github.com/go-openapi/spec
2018/07/23 17:28:46 · Skipping (existing): github.com/sirupsen/logrus
2018/07/23 17:28:46 · Skipping (existing): github.com/emicklei/go-restful
$ rm -fr vendor/github.com/Sirupsen/
$ git reset HEAD vendor/manifest
$ git checkout -- vendor/manifest
$ gvt delete github.com/sirupsen/logrus
$ gvt fetch --tag v1.0.6 github.com/sirupsen/logrus
```
it was gone.

```
$ gvt delete github.com/weaveworks/weave/common
$ gvt fetch --revision 4da998ab4507b6a4852bf341b5df68eb7fca8a57 github.com/weaveworks/weave/common
2018/07/23 17:21:52 Fetching: github.com/weaveworks/weave/common
2018/07/23 17:22:05 · Fetching recursive dependency: github.com/weaveworks/weave/vendor/github.com/fsouza/go-dockerclient
2018/07/23 17:22:05 ·· Fetching recursive dependency: github.com/weaveworks/weave/vendor/github.com/docker/docker/pkg/archive
2018/07/23 17:22:05 ··· Fetching recursive dependency: github.com/weaveworks/weave/vendor/github.com/docker/docker/pkg/system
2018/07/23 17:22:05 ···· Fetching recursive dependency: github.com/weaveworks/weave/vendor/github.com/opencontainers/image-spec/specs-go/v1
2018/07/23 17:22:05 ····· Fetching recursive dependency: github.com/weaveworks/weave/vendor/github.com/opencontainers/go-digest
2018/07/23 17:22:05 ····· Fetching recursive dependency: github.com/weaveworks/weave/vendor/github.com/opencontainers/image-spec/specs-go
2018/07/23 17:22:05 ···· Fetching recursive dependency: github.com/weaveworks/weave/vendor/golang.org/x/sys/unix
2018/07/23 17:22:05 ···· Fetching recursive dependency: github.com/weaveworks/weave/vendor/github.com/docker/go-units
2018/07/23 17:22:05 ···· Fetching recursive dependency: github.com/weaveworks/weave/vendor/github.com/containerd/continuity/pathdriver
2018/07/23 17:22:05 ···· Fetching recursive dependency: github.com/weaveworks/weave/vendor/github.com/Microsoft/go-winio
2018/07/23 17:22:05 ····· Fetching recursive dependency: github.com/weaveworks/weave/vendor/golang.org/x/sys/windows
2018/07/23 17:22:05 ···· Fetching recursive dependency: github.com/weaveworks/weave/vendor/github.com/docker/docker/pkg/mount
2018/07/23 17:22:05 ····· Fetching recursive dependency: github.com/weaveworks/weave/vendor/github.com/sirupsen/logrus
2018/07/23 17:22:05 ······ Fetching recursive dependency: github.com/weaveworks/weave/vendor/golang.org/x/crypto/ssh/terminal
2018/07/23 17:22:06 ···· Fetching recursive dependency: github.com/weaveworks/weave/vendor/github.com/pkg/errors
2018/07/23 17:22:06 ··· Fetching recursive dependency: github.com/weaveworks/weave/vendor/github.com/docker/docker/pkg/longpath
2018/07/23 17:22:06 ··· Fetching recursive dependency: github.com/weaveworks/weave/vendor/github.com/docker/docker/pkg/idtools
2018/07/23 17:22:06 ···· Fetching recursive dependency: github.com/weaveworks/weave/vendor/github.com/opencontainers/runc/libcontainer/user
2018/07/23 17:22:06 ··· Fetching recursive dependency: github.com/weaveworks/weave/vendor/github.com/docker/docker/pkg/fileutils
2018/07/23 17:22:06 ··· Fetching recursive dependency: github.com/weaveworks/weave/vendor/github.com/docker/docker/pkg/pools
2018/07/23 17:22:06 ···· Fetching recursive dependency: github.com/weaveworks/weave/vendor/github.com/docker/docker/pkg/ioutils
2018/07/23 17:22:06 ····· Fetching recursive dependency: github.com/weaveworks/weave/vendor/golang.org/x/net/context
2018/07/23 17:22:06 ··· Fetching recursive dependency: github.com/weaveworks/weave/vendor/github.com/opencontainers/runc/libcontainer/system
2018/07/23 17:22:06 ·· Fetching recursive dependency: github.com/weaveworks/weave/vendor/github.com/docker/docker/opts
2018/07/23 17:22:06 ··· Fetching recursive dependency: github.com/weaveworks/weave/vendor/github.com/docker/docker/api/types
2018/07/23 17:22:06 ···· Fetching recursive dependency: github.com/weaveworks/weave/vendor/github.com/gogo/protobuf/proto
2018/07/23 17:22:06 ···· Fetching recursive dependency: github.com/weaveworks/weave/vendor/github.com/docker/go-connections/nat
2018/07/23 17:22:06 ·· Fetching recursive dependency: github.com/weaveworks/weave/vendor/github.com/docker/docker/pkg/stdcopy
2018/07/23 17:22:06 ·· Fetching recursive dependency: github.com/weaveworks/weave/vendor/github.com/docker/docker/pkg/homedir
2018/07/23 17:22:06 ·· Fetching recursive dependency: github.com/weaveworks/weave/vendor/github.com/docker/docker/pkg/jsonmessage
2018/07/23 17:22:06 ··· Fetching recursive dependency: github.com/weaveworks/weave/vendor/github.com/Nvveen/Gotty
2018/07/23 17:22:06 ··· Fetching recursive dependency: github.com/weaveworks/weave/vendor/github.com/docker/docker/pkg/term
2018/07/23 17:22:06 ···· Fetching recursive dependency: github.com/weaveworks/weave/vendor/github.com/Azure/go-ansiterm/winterm
2018/07/23 17:22:06 ····· Fetching recursive dependency: github.com/weaveworks/weave/vendor/github.com/Azure/go-ansiterm
2018/07/23 17:22:06 · Fetching recursive dependency: github.com/weaveworks/weave/vendor/github.com/weaveworks/go-odp/odp
```

```
$ gvt delete github.com/opencontainers/runc/libcontainer/cgroups
$ gvt delete github.com/opencontainers/runc/libcontainer/configs
$ gvt delete github.com/opencontainers/runc/libcontainer/system
$ gvt delete github.com/opencontainers/runc/libcontainer/user
$ gvt delete github.com/opencontainers/runc/libcontainer/utils
$ gvt fetch --tag v1.0.0-rc5 github.com/opencontainers/runc/libcontainer
2018/07/23 17:08:18 Fetching: github.com/opencontainers/runc/libcontainer
2018/07/23 17:08:24 · Fetching recursive dependency: github.com/opencontainers/runc/vendor/github.com/vishvananda/netlink
2018/07/23 17:08:24 · Fetching recursive dependency: github.com/opencontainers/runc/vendor/golang.org/x/sys/unix
2018/07/23 17:08:24 · Fetching recursive dependency: github.com/opencontainers/runc/vendor/github.com/cyphar/filepath-securejoin
2018/07/23 17:08:24 ·· Fetching recursive dependency: github.com/opencontainers/runc/vendor/github.com/pkg/errors
2018/07/23 17:08:24 · Fetching recursive dependency: github.com/opencontainers/runc/vendor/github.com/opencontainers/selinux/go-selinux/label
2018/07/23 17:08:25 ·· Fetching recursive dependency: github.com/opencontainers/runc/vendor/github.com/opencontainers/selinux/go-selinux
2018/07/23 17:08:25 · Fetching recursive dependency: github.com/opencontainers/runc/vendor/github.com/containerd/console
2018/07/23 17:08:25 ·· Fetching recursive dependency: github.com/opencontainers/runc/vendor/golang.org/x/sys/windows
2018/07/23 17:08:25 · Fetching recursive dependency: github.com/opencontainers/runc/vendor/github.com/sirupsen/logrus
2018/07/23 17:08:25 · Fetching recursive dependency: github.com/opencontainers/runc/vendor/github.com/godbus/dbus
2018/07/23 17:08:25 · Fetching recursive dependency: github.com/opencontainers/runc/vendor/github.com/mrunalp/fileutils
2018/07/23 17:08:25 · Fetching recursive dependency: github.com/opencontainers/runc/vendor/github.com/coreos/go-systemd/util
2018/07/23 17:08:25 ·· Fetching recursive dependency: github.com/opencontainers/runc/vendor/github.com/coreos/pkg/dlopen
2018/07/23 17:08:25 · Fetching recursive dependency: github.com/opencontainers/runc/vendor/github.com/golang/protobuf/proto
2018/07/23 17:08:25 · Fetching recursive dependency: github.com/opencontainers/runc/vendor/github.com/syndtr/gocapability/capability
2018/07/23 17:08:25 · Fetching recursive dependency: github.com/opencontainers/runc/vendor/github.com/coreos/go-systemd/dbus
2018/07/23 17:08:25 · Fetching recursive dependency: github.com/opencontainers/runc/vendor/github.com/opencontainers/runtime-spec/specs-go
2018/07/23 17:08:25 · Fetching recursive dependency: github.com/opencontainers/runc/vendor/github.com/seccomp/libseccomp-golang
2018/07/23 17:08:25 · Fetching recursive dependency: github.com/opencontainers/runc/vendor/github.com/docker/go-units
```

```
gvt delete github.com/fsouza/go-dockerclient
gvt delete github.com/docker/docker/opts
gvt delete github.com/docker/docker/pkg/archive
gvt delete github.com/docker/docker/pkg/fileutils
gvt delete github.com/docker/docker/pkg/homedir
gvt delete github.com/docker/docker/pkg/idtools
gvt delete github.com/docker/docker/pkg/ioutils
gvt delete github.com/docker/docker/pkg/longpath
gvt delete github.com/docker/docker/pkg/mflag
gvt delete github.com/docker/docker/pkg/mount
gvt delete github.com/docker/docker/pkg/parsers
gvt delete github.com/docker/docker/pkg/pools
gvt delete github.com/docker/docker/pkg/promise
gvt delete github.com/docker/docker/pkg/stdcopy
gvt delete github.com/docker/docker/pkg/system
gvt delete github.com/docker/docker/pkg/term
gvt delete github.com/docker/docker/pkg/units
gvt delete github.com/docker/libcontainer/cgroups
gvt delete github.com/docker/distribution/digest
gvt delete github.com/docker/distribution/reference
gvt delete github.com/docker/distribution/vendor/github.com/stevvooe/resumable
gvt fetch --tag 1.2.0 github.com/fsouza/go-dockerclient
2018/07/23 17:03:36 Fetching: github.com/fsouza/go-dockerclient
2018/07/23 17:03:39 · Skipping (existing): github.com/docker/go-units
2018/07/23 17:03:39 · Fetching recursive dependency: github.com/docker/docker/pkg/jsonmessage
2018/07/23 17:03:51 ·· Fetching recursive dependency: github.com/docker/docker/vendor/github.com/Nvveen/Gotty
2018/07/23 17:03:51 ·· Fetching recursive dependency: github.com/docker/docker/vendor/github.com/docker/go-units
2018/07/23 17:03:51 ·· Fetching recursive dependency: github.com/docker/docker/pkg/term
2018/07/23 17:03:51 ··· Fetching recursive dependency: github.com/docker/docker/vendor/github.com/Azure/go-ansiterm
2018/07/23 17:03:51 ··· Fetching recursive dependency: github.com/docker/docker/vendor/github.com/sirupsen/logrus
2018/07/23 17:03:51 ···· Fetching recursive dependency: github.com/docker/docker/vendor/golang.org/x/sys/unix
2018/07/23 17:03:51 ···· Fetching recursive dependency: github.com/docker/docker/vendor/golang.org/x/crypto/ssh/terminal
2018/07/23 17:03:51 ····· Fetching recursive dependency: github.com/docker/docker/vendor/golang.org/x/sys/windows
2018/07/23 17:03:51 · Skipping (existing): github.com/gorilla/mux
2018/07/23 17:03:51 · Fetching recursive dependency: github.com/docker/docker/api/types/swarm
2018/07/23 17:03:51 ·· Fetching recursive dependency: github.com/docker/docker/api/types/network
2018/07/23 17:03:51 ··· Fetching recursive dependency: github.com/docker/docker/api/types/filters
2018/07/23 17:03:51 ···· Fetching recursive dependency: github.com/docker/docker/api/types/versions
2018/07/23 17:03:51 ····· Fetching recursive dependency: github.com/docker/docker/vendor/github.com/docker/go-connections/nat
2018/07/23 17:03:51 ····· Fetching recursive dependency: github.com/docker/docker/api/types
2018/07/23 17:03:51 ······ Fetching recursive dependency: github.com/docker/docker/errdefs
2018/07/23 17:03:51 ······ Fetching recursive dependency: github.com/docker/docker/pkg/streamformatter
2018/07/23 17:03:51 ······· Fetching recursive dependency: github.com/docker/docker/pkg/progress
2018/07/23 17:03:51 ········ Fetching recursive dependency: github.com/docker/docker/vendor/golang.org/x/time/rate
2018/07/23 17:03:51 ········· Fetching recursive dependency: github.com/docker/docker/vendor/golang.org/x/net/context
2018/07/23 17:03:52 ······ Fetching recursive dependency: github.com/docker/docker/vendor/github.com/gogo/protobuf/proto
2018/07/23 17:03:52 ······ Fetching recursive dependency: github.com/docker/docker/vendor/github.com/opencontainers/image-spec/specs-go/v1
2018/07/23 17:03:52 ······· Fetching recursive dependency: github.com/docker/docker/vendor/github.com/opencontainers/go-digest
2018/07/23 17:03:52 ······· Fetching recursive dependency: github.com/docker/docker/vendor/github.com/opencontainers/image-spec/specs-go
2018/07/23 17:03:52 · Fetching recursive dependency: github.com/docker/docker/pkg/homedir
2018/07/23 17:03:52 ·· Fetching recursive dependency: github.com/docker/docker/pkg/idtools
2018/07/23 17:03:52 ··· Fetching recursive dependency: github.com/docker/docker/pkg/system
2018/07/23 17:03:52 ···· Fetching recursive dependency: github.com/docker/docker/vendor/github.com/pkg/errors
2018/07/23 17:03:52 ···· Fetching recursive dependency: github.com/docker/docker/vendor/github.com/Microsoft/go-winio
2018/07/23 17:03:52 ···· Fetching recursive dependency: github.com/docker/docker/vendor/github.com/containerd/continuity/pathdriver
2018/07/23 17:03:52 ···· Fetching recursive dependency: github.com/docker/docker/pkg/mount
2018/07/23 17:03:52 ··· Fetching recursive dependency: github.com/docker/docker/vendor/github.com/opencontainers/runc/libcontainer/user
2018/07/23 17:03:52 · Fetching recursive dependency: github.com/docker/docker/pkg/stdcopy
2018/07/23 17:03:52 · Fetching recursive dependency: github.com/docker/docker/pkg/archive
2018/07/23 17:03:52 ·· Fetching recursive dependency: github.com/docker/docker/pkg/pools
2018/07/23 17:03:52 ··· Fetching recursive dependency: github.com/docker/docker/pkg/ioutils
2018/07/23 17:03:52 ···· Fetching recursive dependency: github.com/docker/docker/pkg/longpath
2018/07/23 17:03:52 ·· Fetching recursive dependency: github.com/docker/docker/vendor/github.com/opencontainers/runc/libcontainer/system
2018/07/23 17:03:52 ·· Fetching recursive dependency: github.com/docker/docker/pkg/fileutils
2018/07/23 17:03:52 ·· Fetching recursive dependency: github.com/docker/docker/vendor/archive/tar
2018/07/23 17:03:52 · Skipping (existing): golang.org/x/net/context
2018/07/23 17:03:52 · Fetching recursive dependency: github.com/docker/docker/opts
2018/07/23 17:03:53 ·· Fetching recursive dependency: github.com/docker/docker/vendor/github.com/docker/libnetwork/ipamutils
2018/07/23 17:03:53 · Skipping (existing): golang.org/x/net/context/ctxhttp
2018/07/23 17:03:53 · Fetching recursive dependency: github.com/Microsoft/go-winio
2018/07/23 17:03:55 ·· Fetching recursive dependency: golang.org/x/sys/windows
```

In order to remove dependencies on `Sirupsen/logrus` while emicklei/go-restful-openapi/pull/49 is getting reviewed and, hopefully, merged:
```
$ gvt delete github.com/emicklei/go-restful-openapi
$ gvt fetch --branch lowercase-sirupsen --revision 129557de7d9f2d2ca4a90cd31c379db90a561ad8 github.com/marccarre/go-restful-openapi
2018/07/23 15:50:36 Fetching: github.com/marccarre/go-restful-openapi
2018/07/23 15:50:38 · Skipping (existing): github.com/emicklei/go-restful
2018/07/23 15:50:38 · Skipping (existing): github.com/sirupsen/logrus
2018/07/23 15:50:38 · Skipping (existing): github.com/go-openapi/spec
2018/07/23 15:50:38 · Fetching recursive dependency: github.com/emicklei/go-restful-openapi
2018/07/23 15:50:40 ·· Skipping (existing): github.com/emicklei/go-restful
2018/07/23 15:50:40 ·· Fetching recursive dependency: github.com/Sirupsen/logrus
2018/07/23 15:50:43 ··· Skipping (existing): golang.org/x/sys/unix
2018/07/23 15:50:43 ··· Skipping (existing): golang.org/x/crypto/ssh/terminal
2018/07/23 15:50:43 ··· Skipping (existing): github.com/sirupsen/logrus
2018/07/23 15:50:43 ·· Skipping (existing): github.com/go-openapi/spec
```

```
$ gvt delete github.com/Azure/go-ansiterm
$ gvt fetch --revision d6e3b3328b783f23731bc4d058875b0371ff8109 github.com/Azure/go-ansiterm
2018/07/23 15:45:10 Fetching: github.com/Azure/go-ansiterm
```

```
$ git grep -l Sirupsen | grep -v vendor | xargs sed -i '' 's:github.com/Sirupsen/logrus:github.com/sirupsen/logrus:g'
$ gofmt -s -w app
$ gofmt -s -w common
$ gofmt -s -w probe
$ gofmt -s -w prog
$ gofmt -s -w tools
```

```
$ gvt delete github.com/weaveworks/billing-client
$ gvt fetch --revision b2b68b13b5af3bc1c13cf9b065845a1e0d9f81e7 github.com/weaveworks/billing-client
2018/07/23 15:35:22 Fetching: github.com/weaveworks/billing-client
2018/07/23 15:35:24 · Skipping (existing): github.com/fluent/fluent-logger-golang/fluent
2018/07/23 15:35:24 · Skipping (existing): github.com/sirupsen/logrus
2018/07/23 15:35:24 · Skipping (existing): github.com/prometheus/client_golang/prometheus
2018/07/23 15:35:24 · Skipping (existing): github.com/weaveworks/common/instrument
```

```
$ gvt delete github.com/weaveworks/common
$ gvt fetch --revision 4d96fd8dcf2c7b417912c6219b310112cb4a4626 github.com/weaveworks/common
2018/07/23 15:31:11 Fetching: github.com/weaveworks/common
2018/07/23 15:31:14 · Skipping (existing): github.com/golang/protobuf/ptypes/any
2018/07/23 15:31:14 · Fetching recursive dependency: github.com/pkg/errors
2018/07/23 15:31:16 · Skipping (existing): github.com/aws/aws-sdk-go/aws
2018/07/23 15:31:16 · Fetching recursive dependency: github.com/sirupsen/logrus
2018/07/23 15:31:18 ·· Skipping (existing): golang.org/x/sys/unix
2018/07/23 15:31:18 ·· Skipping (existing): golang.org/x/crypto/ssh/terminal
2018/07/23 15:31:18 · Skipping (existing): google.golang.org/grpc/status
2018/07/23 15:31:18 · Skipping (existing): github.com/gorilla/mux
2018/07/23 15:31:18 · Fetching recursive dependency: github.com/opentracing-contrib/go-stdlib/nethttp
2018/07/23 15:31:20 ·· Skipping (existing): github.com/opentracing/opentracing-go/ext
2018/07/23 15:31:20 ·· Skipping (existing): github.com/opentracing/opentracing-go/log
2018/07/23 15:31:20 ·· Skipping (existing): github.com/opentracing/opentracing-go
2018/07/23 15:31:20 · Skipping (existing): github.com/prometheus/client_golang/prometheus
2018/07/23 15:31:20 · Skipping (existing): google.golang.org/grpc
2018/07/23 15:31:20 · Skipping (existing): github.com/pmezard/go-difflib/difflib
2018/07/23 15:31:20 · Fetching recursive dependency: github.com/go-kit/kit/log
2018/07/23 15:31:23 ·· Fetching recursive dependency: github.com/go-logfmt/logfmt
2018/07/23 15:31:25 ··· Fetching recursive dependency: github.com/kr/logfmt
2018/07/23 15:31:27 ·· Fetching recursive dependency: github.com/go-stack/stack
2018/07/23 15:31:29 · Fetching recursive dependency: google.golang.org/genproto/googleapis/rpc/status
2018/07/23 15:31:37 ·· Skipping (existing): github.com/golang/protobuf/proto
2018/07/23 15:31:37 ·· Skipping (existing): github.com/golang/protobuf/ptypes/any
2018/07/23 15:31:37 · Skipping (existing): github.com/opentracing/opentracing-go/log
2018/07/23 15:31:37 · Fetching recursive dependency: github.com/sercand/kuberesolver
2018/07/23 15:31:39 ·· Skipping (existing): google.golang.org/grpc/grpclog
2018/07/23 15:31:39 ·· Skipping (existing): google.golang.org/grpc/resolver
2018/07/23 15:31:39 ·· Skipping (existing): golang.org/x/net/context
2018/07/23 15:31:39 · Skipping (existing): google.golang.org/grpc/metadata
2018/07/23 15:31:39 · Skipping (existing): github.com/opentracing/opentracing-go/ext
2018/07/23 15:31:39 · Skipping (existing): github.com/armon/go-socks5
2018/07/23 15:31:39 · Skipping (existing): github.com/opentracing/opentracing-go
2018/07/23 15:31:39 · Skipping (existing): github.com/davecgh/go-spew/spew
2018/07/23 15:31:39 · Skipping (existing): github.com/golang/protobuf/ptypes
2018/07/23 15:31:39 · Skipping (existing): github.com/golang/protobuf/proto
2018/07/23 15:31:39 · Fetching recursive dependency: github.com/grpc-ecosystem/grpc-opentracing/go/otgrpc
2018/07/23 15:31:41 ·· Skipping (existing): github.com/opentracing/opentracing-go/log
2018/07/23 15:31:41 ·· Skipping (existing): golang.org/x/net/context
2018/07/23 15:31:41 ·· Skipping (existing): google.golang.org/grpc/codes
2018/07/23 15:31:41 ·· Skipping (existing): github.com/golang/protobuf/proto
2018/07/23 15:31:41 ·· Skipping (existing): github.com/opentracing/opentracing-go
2018/07/23 15:31:41 ·· Skipping (existing): github.com/opentracing/opentracing-go/ext
2018/07/23 15:31:41 ·· Skipping (existing): google.golang.org/grpc
2018/07/23 15:31:41 ·· Skipping (existing): google.golang.org/grpc/metadata
2018/07/23 15:31:41 ·· Skipping (existing): google.golang.org/grpc/status
2018/07/23 15:31:41 · Fetching recursive dependency: github.com/uber/jaeger-client-go/config
2018/07/23 15:31:44 ·· Fetching recursive dependency: github.com/uber/jaeger-client-go/internal/throttler/remote
2018/07/23 15:31:44 ··· Fetching recursive dependency: github.com/uber/jaeger-client-go/utils
2018/07/23 15:31:44 ···· Fetching recursive dependency: github.com/uber/jaeger-client-go/thrift
2018/07/23 15:31:44 ···· Fetching recursive dependency: github.com/uber/jaeger-client-go/thrift-gen/agent
2018/07/23 15:31:44 ····· Fetching recursive dependency: github.com/uber/jaeger-client-go/thrift-gen/jaeger
2018/07/23 15:31:44 ····· Fetching recursive dependency: github.com/uber/jaeger-client-go/thrift-gen/zipkincore
2018/07/23 15:31:44 ··· Fetching recursive dependency: github.com/uber/jaeger-client-go
2018/07/23 15:31:44 ···· Fetching recursive dependency: github.com/crossdock/crossdock-go
2018/07/23 15:31:46 ····· Skipping (existing): github.com/davecgh/go-spew/spew
2018/07/23 15:31:46 ····· Skipping (existing): golang.org/x/net/context/ctxhttp
2018/07/23 15:31:46 ····· Skipping (existing): golang.org/x/net/context
2018/07/23 15:31:46 ····· Skipping (existing): github.com/pmezard/go-difflib/difflib
2018/07/23 15:31:46 ···· Skipping (existing): github.com/opentracing/opentracing-go/log
2018/07/23 15:31:46 ···· Fetching recursive dependency: go.uber.org/zap/zapcore
2018/07/23 15:31:49 ····· Fetching recursive dependency: go.uber.org/atomic
2018/07/23 15:31:51 ····· Fetching recursive dependency: go.uber.org/zap/internal/bufferpool
2018/07/23 15:31:51 ······ Fetching recursive dependency: go.uber.org/zap/buffer
2018/07/23 15:31:51 ····· Fetching recursive dependency: go.uber.org/multierr
2018/07/23 15:31:54 ····· Fetching recursive dependency: go.uber.org/zap/internal/exit
2018/07/23 15:31:54 ····· Fetching recursive dependency: go.uber.org/zap/internal/color
2018/07/23 15:31:54 ···· Fetching recursive dependency: go.uber.org/zap
2018/07/23 15:31:54 ···· Skipping (existing): github.com/opentracing/opentracing-go
2018/07/23 15:31:54 ···· Skipping (existing): github.com/opentracing/opentracing-go/ext
2018/07/23 15:31:54 ···· Fetching recursive dependency: github.com/uber/jaeger-lib/metrics
2018/07/23 15:31:56 ····· Fetching recursive dependency: github.com/uber-go/tally
2018/07/23 15:31:58 ······ Fetching recursive dependency: github.com/m3db/prometheus_client_golang/prometheus/promhttp
2018/07/23 15:32:00 ······· Skipping (existing): github.com/prometheus/client_golang/prometheus
2018/07/23 15:32:00 ······· Skipping (existing): github.com/prometheus/common/expfmt
2018/07/23 15:32:00 ······· Skipping (existing): github.com/prometheus/client_model/go
2018/07/23 15:32:00 ······ Fetching recursive dependency: gopkg.in/validator.v2
2018/07/23 15:32:06 ······ Fetching recursive dependency: github.com/cactus/go-statsd-client/statsd
2018/07/23 15:32:08 ······ Skipping (existing): gopkg.in/yaml.v2
2018/07/23 15:32:08 ······ Fetching recursive dependency: github.com/m3db/prometheus_client_golang/prometheus
2018/07/23 15:32:08 ······· Skipping (existing): github.com/prometheus/procfs
2018/07/23 15:32:08 ······· Skipping (existing): github.com/prometheus/client_model/go
2018/07/23 15:32:08 ······· Skipping (existing): github.com/prometheus/common/expfmt
2018/07/23 15:32:08 ······· Skipping (existing): golang.org/x/net/context
2018/07/23 15:32:08 ······· Skipping (existing): github.com/beorn7/perks/quantile
2018/07/23 15:32:08 ······· Skipping (existing): github.com/golang/protobuf/proto
2018/07/23 15:32:08 ······· Skipping (existing): github.com/prometheus/common/model
2018/07/23 15:32:08 ······· Skipping (existing): github.com/prometheus/client_golang/prometheus
2018/07/23 15:32:08 ······ Fetching recursive dependency: github.com/apache/thrift/lib/go/thrift
2018/07/23 15:32:13 ····· Skipping (existing): github.com/stretchr/testify/assert
2018/07/23 15:32:13 ····· Fetching recursive dependency: github.com/go-kit/kit/metrics/influx
2018/07/23 15:32:13 ······ Fetching recursive dependency: github.com/influxdata/influxdb/client/v2
2018/07/23 15:32:17 ······· Fetching recursive dependency: github.com/influxdata/influxdb/models
2018/07/23 15:32:17 ········ Fetching recursive dependency: github.com/influxdata/influxdb/pkg/escape
2018/07/23 15:32:17 ······ Fetching recursive dependency: github.com/go-kit/kit/metrics
2018/07/23 15:32:17 ······· Fetching recursive dependency: github.com/performancecopilot/speed
2018/07/23 15:32:19 ······· Fetching recursive dependency: github.com/aws/aws-sdk-go-v2/aws
2018/07/23 15:32:28 ········ Fetching recursive dependency: github.com/aws/aws-sdk-go-v2/internal/sdk
2018/07/23 15:32:28 ········ Skipping (existing): github.com/go-ini/ini
2018/07/23 15:32:28 ········ Fetching recursive dependency: github.com/aws/aws-sdk-go-v2/service/sts
2018/07/23 15:32:28 ········· Fetching recursive dependency: github.com/aws/aws-sdk-go-v2/private/protocol/query
2018/07/23 15:32:28 ·········· Fetching recursive dependency: github.com/aws/aws-sdk-go-v2/private/protocol
2018/07/23 15:32:28 ········· Fetching recursive dependency: github.com/aws/aws-sdk-go-v2/internal/awsutil
2018/07/23 15:32:28 ·········· Skipping (existing): github.com/jmespath/go-jmespath
2018/07/23 15:32:28 ······· Fetching recursive dependency: github.com/aws/aws-sdk-go-v2/service/cloudwatch
2018/07/23 15:32:29 ······· Skipping (existing): github.com/aws/aws-sdk-go/aws
2018/07/23 15:32:29 ······· Skipping (existing): github.com/prometheus/client_golang/prometheus
2018/07/23 15:32:29 ······· Skipping (existing): github.com/aws/aws-sdk-go/service/cloudwatch
2018/07/23 15:32:29 ······· Skipping (existing): github.com/aws/aws-sdk-go/service/cloudwatch/cloudwatchiface
2018/07/23 15:32:29 ······· Fetching recursive dependency: golang.org/x/sync/errgroup
2018/07/23 15:32:31 ········ Skipping (existing): golang.org/x/net/context
2018/07/23 15:32:31 ······· Fetching recursive dependency: github.com/go-kit/kit/util/conn
2018/07/23 15:32:31 ······· Fetching recursive dependency: github.com/VividCortex/gohistogram
2018/07/23 15:32:33 ····· Skipping (existing): github.com/prometheus/client_golang/prometheus
2018/07/23 15:32:33 ····· Fetching recursive dependency: github.com/codahale/hdrhistogram
2018/07/23 15:32:35 ·· Skipping (existing): github.com/opentracing/opentracing-go
2018/07/23 15:32:35 · Fetching recursive dependency: github.com/mwitkow/go-grpc-middleware
2018/07/23 15:32:37 ·· Fetching recursive dependency: github.com/grpc-ecosystem/go-grpc-middleware/logging
2018/07/23 15:32:39 ··· Fetching recursive dependency: github.com/grpc-ecosystem/go-grpc-middleware
2018/07/23 15:32:39 ···· Fetching recursive dependency: github.com/golang/protobuf/jsonpb
2018/07/23 15:32:42 ····· Skipping (existing): github.com/golang/protobuf/ptypes/timestamp
2018/07/23 15:32:42 ····· Skipping (existing): github.com/golang/protobuf/proto
2018/07/23 15:32:42 ····· Skipping (existing): github.com/golang/protobuf/ptypes/duration
2018/07/23 15:32:42 ····· Skipping (existing): github.com/golang/protobuf/ptypes/any
2018/07/23 15:32:42 ····· Skipping (existing): github.com/golang/protobuf/ptypes/struct
2018/07/23 15:32:42 ····· Skipping (existing): github.com/golang/protobuf/ptypes/wrappers
2018/07/23 15:32:42 ···· Skipping (existing): google.golang.org/grpc/metadata
2018/07/23 15:32:42 ···· Fetching recursive dependency: github.com/stretchr/testify/suite
2018/07/23 15:32:45 ····· Skipping (existing): github.com/stretchr/testify/assert
2018/07/23 15:32:45 ····· Fetching recursive dependency: github.com/stretchr/testify/require
2018/07/23 15:32:45 ······ Skipping (existing): github.com/stretchr/testify/assert
2018/07/23 15:32:45 ···· Skipping (existing): google.golang.org/grpc/peer
2018/07/23 15:32:45 ···· Skipping (existing): golang.org/x/net/context
2018/07/23 15:32:45 ···· Skipping (existing): golang.org/x/net/trace
2018/07/23 15:32:45 ···· Fetching recursive dependency: github.com/gogo/protobuf/gogoproto
2018/07/23 15:32:48 ····· Fetching recursive dependency: github.com/gogo/protobuf/protoc-gen-gogo/descriptor
2018/07/23 15:32:48 ······ Skipping (existing): github.com/gogo/protobuf/proto
2018/07/23 15:32:48 ····· Skipping (existing): github.com/gogo/protobuf/proto
2018/07/23 15:32:48 ···· Skipping (existing): google.golang.org/grpc/credentials
2018/07/23 15:32:48 ···· Skipping (existing): google.golang.org/grpc
2018/07/23 15:32:48 ···· Skipping (existing): github.com/opentracing/opentracing-go
2018/07/23 15:32:48 ···· Skipping (existing): google.golang.org/grpc/codes
2018/07/23 15:32:48 ···· Skipping (existing): github.com/golang/protobuf/proto
2018/07/23 15:32:48 ···· Skipping (existing): google.golang.org/grpc/grpclog
2018/07/23 15:32:48 ···· Skipping (existing): github.com/opentracing/opentracing-go/ext
2018/07/23 15:32:48 ···· Skipping (existing): github.com/opentracing/opentracing-go/log
2018/07/23 15:32:48 ··· Skipping (existing): golang.org/x/net/context
2018/07/23 15:32:48 ··· Skipping (existing): google.golang.org/grpc
2018/07/23 15:32:48 ··· Skipping (existing): google.golang.org/grpc/grpclog
2018/07/23 15:32:48 ··· Skipping (existing): google.golang.org/grpc/codes
2018/07/23 15:32:48 ··· Skipping (existing): github.com/golang/protobuf/proto
2018/07/23 15:32:48 ·· Skipping (existing): github.com/opentracing/opentracing-go
2018/07/23 15:32:48 ·· Skipping (existing): google.golang.org/grpc
2018/07/23 15:32:48 ·· Skipping (existing): golang.org/x/net/context
2018/07/23 15:32:48 ·· Skipping (existing): google.golang.org/grpc/codes
2018/07/23 15:32:48 ·· Skipping (existing): google.golang.org/grpc/grpclog
2018/07/23 15:32:48 ·· Skipping (existing): github.com/opentracing/opentracing-go/log
2018/07/23 15:32:48 ·· Skipping (existing): google.golang.org/grpc/metadata
2018/07/23 15:32:48 ·· Skipping (existing): google.golang.org/grpc/peer
2018/07/23 15:32:48 ·· Skipping (existing): google.golang.org/grpc/credentials
2018/07/23 15:32:48 ·· Skipping (existing): github.com/golang/protobuf/proto
2018/07/23 15:32:48 ·· Skipping (existing): golang.org/x/net/trace
2018/07/23 15:32:48 ·· Skipping (existing): github.com/opentracing/opentracing-go/ext
2018/07/23 15:32:48 · Fetching recursive dependency: github.com/weaveworks/promrus
2018/07/23 15:32:53 ·· Skipping (existing): gopkg.in/yaml.v2
2018/07/23 15:32:53 ·· Skipping (existing): golang.org/x/net/context/ctxhttp
2018/07/23 15:32:53 ·· Fetching recursive dependency: github.com/stretchr/objx
2018/07/23 15:32:55 ·· Fetching recursive dependency: gopkg.in/alecthomas/kingpin.v2
2018/07/23 15:32:58 ··· Fetching recursive dependency: github.com/alecthomas/units
2018/07/23 15:33:00 ··· Fetching recursive dependency: github.com/alecthomas/template
2018/07/23 15:33:02 ·· Fetching recursive dependency: github.com/julienschmidt/httprouter
2018/07/23 15:33:05 ·· Skipping (existing): golang.org/x/net/context
2018/07/23 15:33:05 · Skipping (existing): github.com/aws/aws-sdk-go/aws/credentials
2018/07/23 15:33:05 · Skipping (existing): github.com/golang/protobuf/ptypes/empty
2018/07/23 15:33:05 · Skipping (existing): golang.org/x/net/context
2018/07/23 15:33:05 · Skipping (existing): golang.org/x/tools/cover
2018/07/23 15:33:05 · Skipping (existing): github.com/mgutz/ansi
```

gvt delete github.com/Sirupsen/logrus

Add issue template for weave scope github repo

Optimise Node.WithLatests()

Optimise WithParents() when there is only one parent

This is more efficient than repeatedly inserting a single value.

To save allocating and re-allocating the data structure by repeated
addition.