Improve cloud provider deployment process

[sqs]

User story

As a developer who wants to use Sourcegraph for my organization's code, I want to deploy Sourcegraph so that my whole organization can access it. This means [for many orgs] installing it on a public cloud provider such as AWS, Google Cloud, DigitalOcean, etc.

Plan

• Close out "EC2 with Terraform milestone in" https://github.com/sourcegraph/deploy-sourcegraph-aws/issues?q=is%3Aissue+is%3Aopen+sort%3Aupdated-desc+milestone%3A%22EC2+with+Terraform%22
• Dogfood https://github.com/sourcegraph/deploy-sourcegraph-aws/ with some teammates
  • @chrismwendt
  • @ggilmore
  • @KattMingMing or @attfarhan
• Get feedback about https://github.com/sourcegraph/deploy-sourcegraph-aws/ from 1 customer
• Figure out which cloud provider to tackle next: Digital Ocean or Google Cloud
  • I will follow the same skeleton used in https://github.com/sourcegraph/deploy-sourcegraph-aws/, but there is some research involved in figuring out the minutae of each cloud provider's offering so that the terrform scripts can be properly ported. It is possible to de-risk this by trying to ask more knowledgeable teammates (e.g. @KattMingMing and DO) for help / and or to take point
• Publish one more terraform guide for the cloud provider selected above Digital Ocean: https://github.com/sourcegraph/deploy-sourcegraph-digitalocean/

[slimsag]

I know this is a tracking issue, but since I have no action items here I am unassigning myself to reflect that. Add me back if there is clear work I need to do here.

[ggilmore]

After discussion with @nicksnyder, I am prioritizing #2579 and https://github.com/sourcegraph/infrastructure/pull/1336 over this issue. The above checklist is still indicative of what needs to be done (most of which @ryan-blunden has already tackled).