Pin `bleach to` version 4.1.0 in setup.py (#397)
Pin `bleach to` version 4.1.0 in setup.py (#397)

Dependency `bleach` was updated to v5.0.0 and django-post_office tests are failing with this version of bleach.

Pinning the version to `bleach<=4.1.0` makes tests run again for now.
ui/django-post_office,ui/django-post_office