repos:
- repo: https://github.com/psf/black
  rev: 19.3b0
  hooks:
  - id: black

repos:
- repo: https://github.com/psf/black
  rev: 19.10b0
  hooks:
  - id: black

- repo: https://github.com/asottile/blacken-docs
  rev: v1.4.0
  hooks:
  - id: blacken-docs

Update black in pre-commit and add blacken-docs.
Update black in pre-commit and add blacken-docs.
