Unclear Flake8 Versioning and Dependencies

[Stephen-Strosko]

Current versions and recent past versions of pytest-flake8 and flake8 produce different results. Specific inconsistencies around E126 pop up often. Current errors can be reproduced with pytest-flake8 version 1.0.7, pytest version 6.2.4 and flake8 version 3.9.2.