Pre commit notes

To install/try it with gitlint:

tools/create-test-repo.sh
virtualenv .venv && source .venv/bin/activate
pip install pre-commit
echo "\
-   repo: https://github.com/jorisroovers/gitlint
    rev:  master
    hooks:
    -   id: gitlint
" > .pre-commit-hooks.yaml && cat .pre-commit-hooks.yaml
pre-commit install