Only add towers in AddTower state
Only add towers in AddTower state

dianwen/oogasalad_TowerDefense,dennis-park/OOGALoompas,sdh31/tower_defense,kevinkdo/oogasalad_OOGALoompas,jordanly/oogasalad_OOGALoompas,codylieu/oogasalad_OOGALoompas,garysheng/tower-defense-game-engine