This allows the container to be tagged with a user friendly image name
(e.g. `redis:3.2`) rather than the image ID (e.g.
`sha256:87856cc39862cec77541d68382e4867d7ccb29a85a17221446c857ddaebca916`).

Useful for human debugging, as well as some debugging and image scanning
tools.

This risks two bad changes:
1. Discrepancy in image resolution between docker and Nomad's image
loader.
  * I checked the image creation paths in Nomad, and noticed that we
either pulled the image or inspect the image with the user provided
name.

2. A race in image tagging where the tag is modified between image
loading and container creation.
  * I, personally, don't think this case is cause for concern, as it is
analogous to the task running a bit later.  As long as the image is
still present, creating the container should be good.

* add vault integration guide in guides section and move current vault integration content to docs section

* complete guide with image

* fix typos

* rename step 6 and fix typos

* fix typos and awkward phrasing along with links

* fix duplicated step #

* fix typo

* fix links so that pages that pointed to the original vault integration content still point there

This affects exec/rawexec drivers

* move current telemetry page to docs

* fix broken links to telemetry doc

Fix linter job

Add support for docker storage options

Docker driver plugin

Co-Authored-By: nickethier <ncethier@gmail.com>

Vault API Client Tweaks

Keep attempting to renew Vault token past locally recorded expiry, just
in case the token was renewed out of band, e.g. on another Nomad server,
until Vault returns an unrecoverable error.

Return Vault TTL info to /agent/self API and `nomad agent-info` command.

Seems like the stats field is a micro-optimization that doesn't justify
the complexity it introduces.  Removing it and computing the stats from
revoking field directly.

Add a gauge to track remaining time-to-live, duration of renewal request API call.

Add CircleCI configuration for website build

docs for affinity

Fix a panic related to batch GC

Vendor update consul template