Adds BishopTest with testMoves

Assertions for basic movement: up left, up right, down left, down right
Satisfies BishopTest::testMoves

+ Bishop should have 13 possible moves
+ Bishop should be able to move to %s
Adds assertion to BishopTest::testMoves for blocked movement

+ Bishop should have four possible moves
+ Bishop should be able to move to %s
Satisfies BishopTest::testMoves

+ Bishop should have four possible moves
+ Bishop should be able to move to %s