update
- removing old InvadersController class.
- adding a new Invaders class.
- now invaders move faster if one of them get killed.
- adding Generic Random class by using c++14 feature.
- implement type checking for template (functions, class)
- eliminate incidental control flow and implement correct tool from STD algorithm header in Invaders class.
- fixed bug, some time the game doesn't end when all invaders killed
- cleanup