Use `tox` for testing and add coverage and flake8
-
tox
seems to be helpful to execute test. So using this tool as default and removing test splitting - Adapt Makefile using tox, remove splitting the test and just keep
test
target. The splitting is now done by tox - Also test using flake8, remove all ignored cases but E203 (this is neccasary for black formating, there would be problems)
- Add stuff created by new tooling to
.gitignore
- Adapt
.gitlab-ci.yml
, explicit add coverage badge regex for pytest.