Failures
==========
0: Testing constructor populated board twice
1: Testing combineLeft() with {{2,2,0,0},{2,2,2,2},{0,0,2,0},{0,0,2,2}}
result:{[2, 2, 0, 0],[2, 2, 2, 2],[0, 0, 2, 0],[0, 0, 2, 2],}
expected:{[4, 0, 0, 0],[4, 0, 4, 0],[0, 0, 2, 0],[0, 0, 4, 0],}
2: Testing combineRight() with {{2,2,0,0},{2,2,2,2},{0,2,0,0},{0,0,2,2}}
result:{[2, 2, 0, 0],[2, 2, 2, 2],[0, 2, 0, 0],[0, 0, 2, 2],}
expected:{[0, 4, 0, 0],[0, 4, 0, 4],[0, 2, 0, 0],[0, 0, 0, 4],}