for comp3211 final project, hkust, 2017fall

1. To play the game:
   $ python run.py

2. To let AI play for you:
   random move:
   $ python run.py -rand
   tree search:
   $ python run.py -nsteplookahead
   expectimax:
   $ python run.py -expectimax

   to change the depth of search, please modify the function argument in game.py, loop()