Skeleton Increase NumLives when Undo

[enor2017]

I notice that the PA2 skeleton will increase numlives instead of decrease when player undo a move that collected extraLife. More concretely, in the skeleton of PA2 GameController Line 82: this.gameState.increaseNumLives(aliveState.collectedExtraLives.size()); should be modified to decreaseNumLives, since the solution of PA1 did so. (In PA1 solution GameController Line 74)

By the way, I'm surprised that the sanity tests in PA2 didn't catch this issue. So are the sanity tests in PA2 complete(i.e., the same as all sanity+hidden tests in PA1)? If not, should we add some tests by ourselves, or we can just leave it alone and no need to further worry about it?

[henryhchchc]

Please refer to the discussions in #12