e7e01ecb55
Add tactical workaround for LP: #1864640 Keep Focal as dev-bundle until neighbouring charms are enabled. To allow running lint on a Python 3.8 system (Focal), unpin flake8. Clean up test-requirements.txt and mock out dependencies rather than installing them in the unit test virtualenv. Change-Id: I9a4a8dc422b8bdcf61b457f7b3ba828008c415d8