Auto-setup HTTPS when deploying to a new cluster:
* Associates new clusters with elastic ips and sampleclean[1|2|3].eecs.berkeley.edu domains.
* Deploys SSL certificates to the master node.
* Configures and run Nginx as a reverse proxy in front of gunicorn (gunicorn doesn't handle intermediate certificates).
* Defaults to self-signed certs if productions credentials aren't available.
* Updates deploy README to reflect changes.