Code review comment for ~afreiberger/charm-grafana:add_tests_and_linting

Hi,

generally looking good. However I get two unit test errors, one is a left-over example, the other missing fixture:

file /home/peter/src/charms/grafana-charm/tests/unit/test_lib.py, line 8
      def test_grafana(self, grafana): E fixture 'grafana' not found > available fixtures: cache, capfd, capfdbinary, caplog, capsys, capsysbinary, cov, doctest_namespace, mock_charm_dir, mock_hookenv_config, mock_layers, mock_remote_unit, monkeypatch, no_cover, pytestconfig, record_property, rec
ord_testsuite_property, record_xml_attribute, recwarn, tmp_path, tmp_path_factory, tmpdir, tmpdir_factory
> use 'pytest --fixtures [testpath]' for help on them.

I've marked some more places with boilerplate code

cheers,
peter.