This PR fixes an incorrect placement of the update stanza in the task
and also links from the env stanza into an example of using the template
block to generate dynamic environment variables.
* Update operating a job, upgrade guide
This PR updates the guide for updating a job to reflect the changes in
Nomad 0.6
* Feedback changes
* Feedback
* Feedback
Remove the reference to `http://localhost:4567` within the Rolling Update
strategy documentation and fix the link to the `nomad plan` command
documentation.
