Goodbye "yaml invalid" pipeline errors, and don't come back!

This tool use the Gitlab API to validate your local .gitlab-ci.yml.
It can be installed as a git pre-commit hook, preventing commit (and so push) of an invalid .gitlab-ci.yml.

The tool itself does not lint anything: it uses the lint API of a Gitlab instance => it needs to be run somewhere with an access to the Gitlab instance where your project come from.