Required fixes:
- CallbackQuery is now comparable.
- Message.effective_attachment, Message.photo,
Message.new_chat_members, Message.new_chat_photo &
Game.text_entitties semantic fixes - when they are not defined,
return an empty list.
- Docstring fix to Update class.
Still need setGameScore (I'm thinking we can set it to the ever increasing
envvar 'TRAVIS_BUILD_NUMBER') and getGameHighScores.
The tests currently don't work... Since I don't really understand how
PhotoSize works... Please halp :P