Typo in comment

Author: JFincher42

arcade-a-primer/arcade_game.py

@@ -94,7 +94,7 @@ def add_enemy(self, delta_time: float):
         """Adds a new enemy to the screen
 
         Arguments:
-            delta_time {float} -- How much time as passed since the last call
+            delta_time {float} -- How much time has passed since the last call
         """
 
         # First, create the new enemy sprite