Splitting

Instead of using asteroid.kill() in our game loop, we'll create and use a new asteroid.split() method.

Add a new .split() method to the Asteroid class. It should:

1. Immediately .kill() itself (think about it: this asteroid is always destroyed, but maybe we'll spawn new smaller ones, depending on its size).
2. If the radius of the asteroid is less than or equal to ASTEROID_MIN_RADIUS, just return; this was a small asteroid and we're done.
3. Otherwise, we need to spawn 2 new asteroids like so:
   1. Call log_event("asteroid_split") (be sure to import log_event at the top of the file).
   2. Call random.uniform to generate a random angle between 20 and 50 degrees (be sure to import the standard random library at the top of the file).
   3. Call the .rotate method on the asteroid's velocity vector to create a new vector representing the first new asteroids movement.
   4. Call the .rotate again for the second new asteroid, but this time rotate it in the opposite direction (negative angle).
   5. Compute the new radius of the smaller asteroids using the formula old_radius - ASTEROID_MIN_RADIUS.
   6. Create two new Asteroid objects at the current asteroid position with the new radius.
   7. Set the first's .velocity to the first new vector, but make it move faster by scaling it up (multiplying) by 1.2.
   8. Do the same for the second asteroid, but with the second new vector.
   9. In the game loop in main.py, replace asteroid.kill() with asteroid.split().
   10. Run the game and shoot some asteroids!

If things seem to be working, run and submit the CLI tests.