pull socket client confirmation into its own function
    * add TODO list to client.js
adds styling for waiting room
    * removes assignment of this.player
    * comments out updateDOM call
ready button returns true if all clients click "ready"
    * upon clicking the ready button, send message to server
    * server adds client to readyClient array
    * server then checks if the lengths are the same
    * if so, return true
waiting room correctly updates View on player disconnect
    * on disconnect, reuse emitClientConfirmation to send all clients
    current status of clients in waiting room
    * retooled addClient for both allClients & readyClients array