Updated to work with latest gevent-socketio 

Hi.  I am new to github, and this is my first pull request.  Apologies if it's not executed correctly.    

Thanks for this great demo.  I updated tictactoe to work with the latest gevent-socketio code with their fancy new django integration in socketio.sdjango.  The changes are based on the django_chat example form the gevent-socketio project. 
https://github.com/abourget/gevent-socketio/tree/master/examples/django_chat 

Let me know if I can improve this request.

thanks.