Restructuring and tests!

1) dominion_game.py is where the actual game will happen along with
   any configurations that might be necessary (eventually configs should
   probably be pulled out)
2) dominion_cards.py will contain all of the card definitions and functions
   unique to a card (i.e. Smithy action, Village action, etc.)
3) dominion_tests.py exists! It tests things. It doesn't test everything
   yet, and it's maybe not the best but it does provide some peace of mind.