Uses Mongo as the database

 - Opens and closes database connection before/after every request -- too slow?
 - Need to double-check that everything is getting closed properly
Refactored game_site, db methods
Removed set_verbs from scaffolding; updated tests
Nested objects serialise and deserialise properly

 - Added a recursive serialisation and deserialisation function to creation.py so that nested objects continue to serialise/deserialise themselves
 - Changed the format of serialisation dictionaries
 - Added an assign_objects function to game.py that adds objects to other objects (in response to "put obj in container" or "get obj from container") so that when container.deserialise() is called, the container object can update its contained objects
 - Added a test to test all of this new functionality
Updated documentation & README