Features

• Switch from pyyaml to ruamel.yaml
  • This enforces (among other things) duplicate key checking in yaml.
  • #351 PR by @asottile.
• Add a new --pattern option to no-commit-to-branch for regex matching branch names.
  • #375 issue by @marcjay.
  • #376 PR by @marcjay.

Fixes

• Set require_serial: true for flake8
  • flake8 internally uses multiprocessing.
  • #358 PR by @asottile.
• Don't run check-executables-have-shebangs / trailing-whitespace hooks during the commit-msg stage.
  • #361 issue by @revolter.
  • #362 PR by @revolter.
• Run check-byte-order-marker against types: [text]
  • #371 PR by @tobywf.
  • #372 PR by @tobywf.
• Do not require UTF-8-encoded files for check-docstring-first
  • #345 issue by @x007007007.
  • #374 PR by @asottile.

Misc.

• pre-commit-hooks now is type checked with mypy.
  • #360 PR by @asottile.