build: Apply goimports formatting to various files

The following files were not formatted as the output of goimports(1)
would create, causing the goimports linter to fail:

command/agent/resources_endpoint.go
nomad/resources_endpoint.go
nomad/resources_endpoint_test.go

Fix number of primary nouns in Nomad

TLS Guide

Thanks @jvoorhis!

Vendor vault test deps

Updated AWS fingerprint test for ami-id

This is a weird one because `make bootstrap` does a `go get vault` so CI
never fails due to missing Vault dependencies. However developer
machines will have whatever version of vault they grabbed last time they
bootstrapped a new dev environment.

This can lead to surprising build issues and different devs testing
slightly different code.

So let's vendor all test deps to try to keep the Nomad repo
self-contained.

Fix documentation bug on json jobs

Added dnsoptions to the docker driver

In https://github.com/hashicorp/nomad/pull/2999, I changed ami-id
to non-unique.  This updates the test to reflect that.

Fix documentation bug: distinct_host -> distinct_hosts

Unmount task directories when alloc is terminal

This PR unmounts directories from tasks when the alloc is terminal
rather than when it is garbage collected.

/cc @angrycub

Fix alloc health with checks using interpolation

Template emits events explaining why it is blocked

Migrate nomad status to nomad job status

AMI ID is potentially non-unique

Code highlighting

This PR does the following:
* Adds a mechanism to emit events in the TaskRunner
* Vendors a new version of Consul-Template that allows extraction of
missing dependencies
* Adds logic to our consul_template.go to determine missing events and
emit them in a batched fashion.
* Refactors the consul_template code to split the run method and take in
a config struct rather than many parameters.

Fixes https://github.com/hashicorp/nomad/issues/2578

Changed the keys map to reflect that.