added Direction and Occupier enums, new methods in the chess board class for getting the neighbor in each of the 8 directions, removed uses of the deprecated getBoard method
added test cases for chess piece class
chess piece junit tests are now passing
the code to add locations to the default board and the chess piece checkAvailable code logic have been cleaned up. Also x coordinate and y coordinate in the location class are now indexed by 0 which is more intuitive