Nginx proxy

- Install nginx into docker image
  - set nginx to not daemonize (important for supervisord to keep control of the process)
  - add an ssl.conf to handle the actual reverse proxying to waitress
  - add a process that creates new certificates in the docker image the first time a fresh container is started.  (The certs are self-signed with a commonname that will never match reality but that's OK; this is a demonstration)
- changed the port that angerona uses internally back to 6543 to keep it consistent with how pyramid waitress apps are normally configured