Release automation staging environment

[dagood]

Currently, release automation has a variable group that points at the set of repos and credentials to use that can be swapped out to point at other repositories. I put this in for my use when initially developing the infra and testing substantial changes later, but I didn't flesh it out to be all that usable. I think these are the key things to address:

• The repos/resources need to exist in a known location where the whole team has access.
• The resources should be private, to mitigate risks with running uncertain changes through this kind of system.
• The environment should have a repeatable setup process.
  • Perhaps each staging release should create its own set of resources upon start. This would also allow multiple to run at the same time.
    • I'm not sure if this is feasible, due to permissions needed to create resources and setup time to copy over all the needed data.