Add docs on how to deploy Athens to ACI

[arschles]

This would increase the options for folks who want to deploy Athens to the cloud

ACI docs: https://azure.microsoft.com/en-us/services/container-instances/

[arschles]

Changed title - copy/paste error on the first try 😆

[arschles]

This would be a great way to get a quick test up and running for a proxy and/or a hosted registry (ACI has auto DNS support)

[michalpristas]

@arschles any progress here? can we consider deployment by @marstr and his team final and close this?
If so maybe the output could be blog post/docs what needs to be done to deploy Athens to ACI, any caveats...

[marstr]

@joshgav for awareness.

We haven't looked into ACI in particular, but it shouldn't be much different from all of the other "run a Container in Azure" solutions.

[arschles]

We should add docs for how to deploy Athens to ACI, but I don't think we should run an official athens instance on ACI because that overlaps with #772

I'll update labels and title accordingly

[arschles]

I have a script at https://github.com/arschles/athens-azure/blob/master/aci.sh. I'll add a sample to the docs