Add a Photo Finish

If there are multiple horses in first place, we could introduce another phase: "photo finish". All it would do is randomly decide who the real winner was, @apaleslimghost suggested something like:

<img width="274" alt="Photo finish with emoji" src="https://user-images.githubusercontent.com/138944/76005324-c2250200-5f02-11ea-89b5-60da747da0c5.png">
