Add support for setting the Availability Zone to support AWS resource…

[dmc5179]

Add support for selecting the Availability Zone in AWS. Not all resources in AWS are available in each zone of a region. Current example being GPU instances. They are available in us-east1-a/c/f but not b. Without this setting it is generally random what Availability Zone the instances end up in.

[dmc5179]

Make sense. I'm not a huge fan of the fact that git lets you manipulate history and I meant to add all of this to a branch in case I needed to make edits which is much easier to do in a PR with a branch. Do you mind if I close this PR, add the original changes, along with your modification requests, to that branch, and then create another PR from there? Sorry for the trouble. It has always bugged me that a revision control system like git lets you change history even when there is a mistake.

[jaredhocutt]

Just make the changes and add as a new commit on your master. It'll automatically update the PR for you and I can squash merge when I accept the PR.

[dmc5179]

OK. I made the changes:

• Removed the default from the example var file so users will have to set it and hopefully not all choose the same
• Added the variable and its description to the README file
• Remove the AZ setting where it was not required as you mentioned
• Updated the AZ setting to use either the user set value or omit the parameter which should result in a semi-random result for those tasks.

[jaredhocutt]

Can you run a test deployment by not setting aws_zone and ensure everything works as it always has? Once you confirm things are good, I'll merge the PR.

Thanks!

[dmc5179]

Sure. I'm going to pull the repo fresh and just run it.