Typo in file zerg_agent_step5.py on line 48 "obs" instead of "oba"

Typo in file zerg_agent_step5.py on line 48 and in file zerg_agent_step6.py
on line 55

larvae = self.get_units_by_type(oba, units.Zerg.Larva)
it should be obs
larvae = self.get_units_by_type(obs, units.Zerg.Larva)