Labelkit

This version includes breaking changes.
- Step params are now set as top-level object properties individually rather than a single `params` dict property created from a `kwargs` object
- Updated examples with new syntax

Bugfixes:
- Importing `labelkit` doesn't fail if openai key isn't present

- Fixes some bugs.
- Implements `update_params` in `Pipeline`

**Full Changelog**: https://github.com/villagecomputing/labelkit/compare/v0.0.1...v0.0.4

Initial release

**Full Changelog**: https://github.com/villagecomputing/labelgen/commits/v0.0.1