CI: add __init__.py to isort skip list
4.3.5 - February 24, 2019 - last Python 2.7 Maintenance Release
This is the final Python 2.x release of isort, and includes the following major changes:

Potentially Interface Breaking:

The -r option for removing imports has been renamed -rm to avoid accidental deletions and confusion with the -rc recursive option.
__init__.py has been removed from the default ignore list. The default ignore list is now empty - with all items needing to be explicitly ignored....