Infrastructure: Easy Rollback

[CCallahanIV]

Currently, in order to rollback a deployment, it must be done through the Heroku dashboard or CLI. It would be best to be able to rollback deployments from the repository or a more commonly available CI/CD pipeline.

Explore possibility of using existing Travis CI pipeline to perform both deploys and rollbacks.

Acceptance Criteria:

1. Any developer that is a Contributor to this project, should be able to roll back deploys.
2. Rollback functionality should be easy to use and readily accessible (e.g. a button on github or Travis CI dashboard)