UI: Log streaming

Changed Superset to only return the resource name

Update community.html.erb to include Levant.

This change requests that Levant be added to the Nomad community page. Levant is an open source templating and deployment tool for HashiCorp Nomad jobs that provides realtime feedback and detailed failure messages upon deployment issues. Further details about Levant can be seen on the [jrasell/levant](https://github.com/jrasell/levant) GitHub page.

The Superset method on Resources used to return a string in the format of “[resource name] exhausted”.
This was leading to the output in plan/create job API DimensionExhausted to return keys like
```
"DimensionExhausted": {"cpu exhausted": 1}
```
This was not anywhere documented, however, one of the examples on the website showed it like this.

The other side effect of this is that the CLI formats the strings from the name of the key leading to output like
```
* Dimension "cpu exhausted" exhausted on 1 nodes
```

Fixed error messges for MeetsMinResources

update API docs for /regions endpoint

API docs: /client/gc returns text/plain, not json

Fix Website Docs for Periodic jobs TimeZone

Minor tweaks to Enterprise docs

This will need to get better for testing the offset stitching
logic in the polling case.

Until they can be mocked, they can't be used

Just verifying the log code works

Supports:
  - Reading the head of a log
  - Reading the tail of a log
  - Following a log in one of two ways:
    - Streaming the HTTP request (using fetch res.getReader)
    - Polling the log endpoint (using EC timeouts)