Merge pull request #27 from ping19/master

Remove comment
Merge pull request #28 from ping19/master

removed other comments
Merge pull request #29 from ping19/master

New class for enemy
add alien1 sprite

added one of the enemy sprites to the sprite folder
Merge pull request #30 from ping19/master

Coded EnemyEntity class to add new sprites
Merge pull request #31 from katiewood/master

add alien1 sprite
Merge remote-tracking branch 'upstream/master'
Merge pull request #32 from ping19/master

Add new sprite to game
Merge remote-tracking branch 'upstream/master'