v.1.1

1. Fixed bug where, after a game over event and a replay, the original ship would "ghost" bullets. In other words, it wouldn't be completely freed from the scene, and would continue firing from its anticipated position alongside the new ship.

2. Added new graphics for the ship! It's my intention to eventually make the ships upgradable and customizable, but that will be down the road. In any case, I used Blender 2.8/Eevee to rapidly model an idea I had based on a stealth fighter, which looks enough like a space fighter to be passable I think.