Replaced pipenv with pip-tools generated requirements files.
Corrected the error in widgets.pyi. This was mostly done because I couldn't get the regex support in pytest-mypy-plugins to work, which meant the test failed locally due to different source repo paths.
Other fixes needed along the way
widgets.pyi. This was mostly done because I couldn't get the regex support in pytest-mypy-plugins to work, which meant the test failed locally due to different source repo paths.