v3.3.3

Version 3.3.3

- Introduce `average`, `maximum`, and `minimum` methods on the Roll
  object, which is handled by the `MinMaxCalc` service class. Max
  returns the highest roll possible, and min naturally returns the
  lowest roll possible, and average returns a float between those.
- Updated the `dicebag` executable to have new options for the above new
  methods.