Dockerfile for Jia and some convenience tooling

This Dockerfile expects a settings.py in /etc/jia/settings.py on the host machine.  I'll include some init.d or supervisord tooling to run the docker instance on the host machine once I figure that out.
this is a good idea, but let's hold off for now.  some of the packages i have here (like pandas) as useful in code mode on the host machine regardless of Jia installation requirements.  Let's make a packages.txt once we know this works in practice?