Basic build for Docker (Work in Progress)

[stellarpower]

Builds the image successfully thus far. The container drops into a shell for playing around.

The master branch complains about the unrecognised ruledir argument and without it says the ruleset fixture isn't found. The 1.2.0 branch throws an "INTERNALERROR" AssertionError with python3 but seems to run in python2.7. I haven't got the time right now to test further.