Rebasing against changes from master
Unreachable code
Undo, redo no effet bug fix
Merge branch 'GameModelTest' of github.com:tmzhuang/pvz-reloaded into GameModelTest
Fix test cases and removed dependency on mockito
Update README.md
Merge branch 'GameModelTest'

Test class for GameModel
removed useless file
Merge branch 'GameModelTest' of https://github.com/tmzhuang/pvz-reloaded into GameModelTest
Merge branch 'GameModelTest'