feat(*): build test-etcd, test-postgresql, and mock-store locally
feat(*): build test-etcd, test-postgresql, and mock-store locally

Previously we were relying on someone manually building and pushing
these to Docker Hub. We should build these with our BUILD_TAG like
we do all components, so that Jenkins can pick up local changes
in a branch.

Joshua-Anderson/controller-sdk-go,Joshua-Anderson/controller-sdk-go