- Add .pre-commit-config.yaml with initial config.
- Add python black pre-commit config
- Apply pre-commit code changes
- Add information to CONTRIBUTING.md
- Add pre-commit to build requirements
- Run pre-commit during travis CI build
- Use a travis build matrix to control when pre-commit runs
in the CI process. Use explicit include to only run
pre-commit on Python 3.9.
56a1935ff0
