* (flake8): remove unused import
* Add sandbox folder to gitignore
* (python): drop python 3.5, add support for python 3.9
* (black): fix unsupported py39 target
* fix flakes complains
* Remove unused import
* Line-break long strings
* Use raw string for regex pattern
* Run black on previous PR
* add invalid template finle name test
* Small improvements in multiple tests
* Add more tests for default remote
* Add notes from JS implementation cross testing
* add integration and unit testing
* refactor integration test
* remove xfail markers from integration tests
* Add integration tests for issue [79](https://gitlab.com/KeNaCo/auto-changelog/issues/79)
Full set of changes: [`0.5.1...0.5.3`](https://gitlab.com/KeNaCo/auto-changelog/compare/0.5.1...0.5.3)