Created Army Ant

Created an .ai file for the Army Ant enemy, added a mockup, and also 3
sprites: one that is whole, and the others are parts for Chris to
manipulate.
-Travis
Added Army Sprites to Zero

CHRIS, PLEASE READ: the sprites are: spr_army_ant_whole - use this for
testing, then also spr_army_ant_hill as the base, and spr_army_gun as
the movable/flipable part for your turret. See me if you have questions.
-Travis
Merge branch 'turret-assets-branch'