Send Game State transmission to all subscribed players on end_turn

[BrennanAyers]

Once we have subscriptions to all Players of a Game set up, and the Game is running (#107), we now can update the Game State for all Players on the end_turn action.

• Player 1 ends their turn, Players 2-4 will receive an ActionCable payload updating their local React app
• Player 2 will now be able to perform actions, as the current_player will be them
• Player 2 ends their turn, Players 1, 3-4 will receive an ActionCable payload updating their local React app
• loop until end of Game