Initial commit.
Html, css, Game, player, invaders, keyboard input done. Shooting back and collision detection todo.
Shooting back done. Game height updated. Collision detection todo.
Merge commit 'db0ed2d254377a0356b3107bfa9ad913673e588d'

* commit 'db0ed2d254377a0356b3107bfa9ad913673e588d':
  Initial commit
Shooting back done. Game height updated. Collision detection todo.