Create Dockerfile for Kronos

Docker has 3 kronos services, one for all, one for readonly, one for collector. When docker is run, all three are started. Three ports are mapped. The log directory is mapped to `/var/log/kronos`. Settings file at `/etc/kronos/settings.py` is mapped into the docker.
we ditched uwsgi.ini---I don't see it in the Dockerfile being copied, and it's still important for ubuntu installation.