Story #3- refactored based on Bill's suggestions:
-removed MessagePrinter class
-deleted viewBoard() method and changed drawBoard() method to use string interpolation-like behavior
Story #3- added Player class, extracted takeTurn() method in Game class to DRY up go() method
Story #4- out prints "Location already taken" while location is taken.
encapsulated methods in Game#takeTurn() method
story  # 5- refactored tests based on Bill's suggestions:
-no more private methods
-dependency injection throughout
-no more than 3 params per constructor
-replaced "Player 1 and Player 2" with "Player X and Player O"
story # 6- We have a winner!