Is twixt a dependency?

[jonathanolson]

It's noted in the package.json, but I don't see any usages in the sim. Can we remove that?

#173

[Denz1994]

At one time we were using our Animation library to handle separating molecules and returning them to the buckets and play area. The implementation has changed and we are not using twixt anymore. The dependency has been removed. Closing.