What I want you to do (try to do it in this order):
In the Space class, add a method called gameOver.
This new method will create a new scoreBoard object and place it in the World.
This method will be called in the Rocket class when there is a collision.
In the Rocket class, add a method called checkCollision.
This new method will check and see if the Rocket is intersecting with an Asteroid object.
If there is an intersection (aka collision), then I want you to:
Put an explosion where the rocket is,
Remove the rocket from the World,
Show the scoreboard.

