Version bump

wumpus/__init__.py

 from wumpus.wumpus import WumpusWorld, Hunter, Wumpus, Pit, Gold, Exit
 from wumpus.gridworld import Agent, Percept, InformedPlayer, UninformedPlayer, UserPlayer, RandomPlayer, Coordinate, coord
 
-__version__ = '0.3.0'
+__version__ = '0.3.1'