* Add default license header to files which have no copyright or license header yet.
* yml extension should have been xml...
(cherry picked from commit 1ab2a5f1bc)
* feat(gitlab-deploy-key): automatically update ...
... the public key
* add integrity test
* fix sanity issues
* added changelog fragment
Co-authored-by: Mirko Wilhelmi <Mirko.Wilhelmi@sma.de>