Push to App Engine when new update to main is performed

[smburdick]

Is your feature request related to a problem? Please describe.
Gcloud deployment is only done through CLI right now.

Describe the solution you'd like
When I merge to main, push to a beta endpoint and check it there. If everything checks it, push to prod endpoint.

Describe alternatives you've considered
This can be low-priority as we are still emerging into the MVP stage

Additional context
Use GitHub workflows for CI/CD.

[Gistbatch]

@smburdick, there is an unofficial GitHub integration for the app engine repo. This requires authenticating with the service, which you can only do as this is hosted on your private cloud.