First draft of clearning up Interaction.py (with a few tiny changes elsewhere).
Change some more 0/1s to Side.RIGHT/LEFTs.
Fix a tiny bug, clean-up TODOs.
Merge pull request #10 from mbforbes/style

This all sounds great!

I'm still slightly worried about introducing bugs so perhaps we can agree on a common testing protocol. The main worry is breaking our go-to demo, so let's agree on what that basic demo is and we can just make sure the demo works before each merge. What do you think?