First version of human vs engine working

First cut changes for starting a new game are now in place. When a
user visits the /new_game page the app adds a new row to the
active_games table and redirects to the /games/:id page where :id
is the id of the newly added row in the active_games table. On
visiting the /games/:id page for now the user is just shown a
string stating that the new game has been started. Also a full
socket.io connection is established and a two way user to chess
engine communication is stated allowing the user to play a game
against the chess engine.