Refactored the Dockerfile and eliminated supervisor

[kMaiSmith]

I removed a bunch of packages and consolidated steps for the docker build to make everything a bit faster and more readable.

The latest version of the this docker image doesn't actually start because of supervisor configuration issue with the path to the java executable; I decided to eliminate supervisor because there's only one service running inside the docker container, making everything more simple.

[karrots]

Makes sense to remove supervisor and handle process crashes and such outside the container by restarting.

[rednut]

will test shortly and merge if cleanly builds