Show release history and allow rollback to previous revision

It would be very useful to be able to get the deployment history for a SAM application from the command line. Right now, a developer relies on git to track to know about the _code_ history, but without full CI/CD, he/she does not have insight into SAM's release history. It would be extremely useful to have that that history. In the spirit of SAM, this should be readily accessible from the command line.

Additionally, it would be very useful to be able to roll back to a previous _release_ as it was deployed previously. This is different than rolling back to a previous version of the code and redeploying. Rolling back would provide confidence that the roll back is to a prior working state as it was in the environment previously.