Class-resolver

What's Changed
* Function resolver by mberr in https://github.com/cthoyt/class-resolver/pull/12
* Add missing tests by cthoyt in https://github.com/cthoyt/class-resolver/pull/13


**Full Changelog**: https://github.com/cthoyt/class-resolver/compare/v0.1.1...v0.2.0

**Full Changelog**: https://github.com/cthoyt/class-resolver/compare/v0.1.0...v0.1.1

- Add special TypeError for unexpected kwargs
- Blacken all code
- Add python 3.6 through 3.10 testing

- Allow override of default value on lookup
- Add special exception when missing a required kwarg

Add entrypoint loader

- Add ability to register classes to a resolver after instantiation
- Add checks for class signature