chore(release): 2.0.0 [skip ci]

# [2.0.0](v1.1.0...v2.0.0) (2019-11-17)

### Features

* **distribution:** library now requires Unity Package Manager to run ([f48f901](f48f901))

### BREAKING CHANGES

* **distribution:** You now must use Unity's Package Manager to install this package. See the `###
Installation` section in the README.md for full details.

Added AnimatorStub, Animator extensions, and upgraded to 2017.3

Merge branch 'release/1.1'

Initial release with AnimatorPlayback objects, AnimatorPlayback unit …

…test coverage, and some helper AnimatorBehaviors.