task shutdown_delay will currently only run if there are registered
services for the task. This implementation detail isn't explicity stated
anywhere and is defined outside of the service stanza.

This change moves shutdown_delay to be evaluated after prekill hooks are
run, outside of any task runner hooks.

just use time.sleep

Upgrade all golang.org/x packages

docs: fix link to envoy proxy documentation on consul site

Upgrade all golang.org/x packages to pick up fixes and improvements.
Some packages date back to 2018 and so much improvement happened since
then!

Prepare for 0.11.1 release

vendor: upgrade golang.org/x/net packages

changelog: add 0.11.0 release date.

golang.org/net packages are ancient - upgrading them to pick up
important fixes, e.g. https://go-review.googlesource.com/c/go/+/87298/

e2e: add a convenient creation script

Add a convenience Makefile for creating e2e environment for manual
debugging.

dev: Use go mod for managing hashicorp/go-msgpack

Use go mod for github.com/hashicorp/go-bindata/go-bindata and
github.com/elazarl/go-bindata-assetfs/go-bindata-assetfs but use
`@master` to pull the latest master.  These packages don't have release
tags so `@master` worksaround it.

tests: deflake some SetServer related tests

docs: update downloads+banner for 0.11.0 GA

docs: move rkt to external drivers

Co-Authored-By: Chris Baker <1675087+cgbaker@users.noreply.github.com>

docs: update changelog/upgrade for 0.11.0

Keep beta label for now.

Co-Authored-By: Buck Doyle <buck@hashicorp.com>

Co-Authored-By: Drew Bailey <2614075+drewbailey@users.noreply.github.com>

Adding `-trimpath` to builds removes the local working directory from
the goroutine stack traces, which makes our builds more reproducible
and doesn't leak information about our local development workstations
or CI environment.

Bumps [next](https://github.com/zeit/next.js) from 9.3.1 to 9.3.2.
- [Release notes](https://github.com/zeit/next.js/releases)
- [Commits](https://github.com/zeit/next.js/compare/v9.3.1...v9.3.2

)
Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

docs: add 0.11.0-rc1 to download page

Bumps [acorn](https://github.com/acornjs/acorn) from 5.7.3 to 5.7.4.
- [Release notes](https://github.com/acornjs/acorn/releases)
- [Commits](https://github.com/acornjs/acorn/compare/5.7.3...5.7.4

)
Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

update banner from "Beta" to "Release Candidate"

Some tests assert on numbers on numbers of servers, e.g.
TestHTTP_AgentSetServers and TestHTTP_AgentListServers_ACL . Though, in dev and
test modes, the agent starts with servers having duplicate entries for
advertised and normalized RPC values, then settles with one unique value after
Raft/Serf re-sets servers with one single unique value.

This leads to flakiness, as the test will fail if assertion runs before Serf
update takes effect.

Here, we update the inital dev handling so it only adds a unique value if the
advertised and normalized values are the same.

Sample log lines illustrating the problem:

```
=== CONT  TestHTTP_AgentSetServers
    TestHTTP_AgentSetServers: testlog.go:34: 2020-04-06T21:47:51.016Z [INFO]  nomad.raft: initial configuration: index=1 servers="[{Suffrage:Voter ID:127.0.0.1:9008 Address:127.0.0.1:9008}]"
    TestHTTP_AgentSetServers: testlog.go:34: 2020-04-06T21:47:51.016Z [INFO]  nomad: serf: EventMemberJoin: TestHTTP_AgentSetServers....