v0.2.2

Breaking change if you are using the ray helper functions that allows us to remove the optional dependencies. The core ruck API remains the same.

• ruck.util._ray moved to ruck.external.ray
• added ruck.external.deap with select_nsga2 that uses deep behind the scenes. The goal is to implement the ourselves in the near future. Currently it is a bit slow, and means me need extra deps.
• More examples!