Add a New Player

Add the second player

Each game needs to add a second player in order to begin play. This really amounts to assigning a value to the :name key for the second player.

We’ll begin with a public client function, add_player/2. This takes the PID of the game process and the second player’s name. We’ll have add_player/2 wrap GenServer.call/2 so it will be synchronous. Then, we need a new clause of handle_call/3 ...