Spike - Think about rollback process for CI

[bmonkman]

In k8s it's easy enough to roll back to a previous version, but the tougher part is integrating it with our current CI tools. For example, last time I looked, there isn't a great way in CircleCI to trigger a new run of a certain pipeline except via API, and we could have it so that there's an approval stage after deploying to production which would do a rollback, but then all the builds would be in "waiting for approval" rather than "success" states. Let's look into if there is a nice way to do this through straightforward workflows in CircleCI or Github. If not, is there another place we could add this functionality? Slack bot? Something else?