Movement work

Let's not merge this yet. I just created this so you can see what I'm working on. You can clone this branch if you want. 
I've added the function moveShipAI in the ship code. This is where all of our work will go.
I'm currently working on checking the distance between the ship and any bullets on the screen to see if it needs to move yet. For some reason I apparently can't math and it's not working.