Test environment

This introduces a Dockerfile and environment.sh to aid in setting up fresh systems/containers to test in.

The environment.sh will attempt to install all databases used in the test suite. It'll probably clobber existing ones, so you probably don't want to run it in an environment you care about.

Note that upon logging in, nothing is running. You can run `supervisord` to spin up all the services needed, or you can run individual components if you want.