Add CircleCI config for both CSPs to:
- build the Docker image and push it to the registry
- run a short-lived k8s job to apply migrations and see data
- update the images for the Flask pods and rq worker pods
Most build tools (i.e., the CircleCI Orbs) expect a Dockerfile in the
repo root. Rather than have to configure an exception everywhere, put it
where most people/tools expect it to be.