Bump pillow from 8.0.1 to 8.1.1 (#108)

Bumps [pillow](https://github.com/python-pillow/Pillow) from 8.0.1 to 8.1.1.
- [Release notes](https://github.com/python-pillow/Pillow/releases)
- [Changelog](https://github.com/python-pillow/Pillow/blob/master/CHANGES.rst)
- [Commits](https://github.com/python-pillow/Pillow/compare/8.0.1...8.1.1)

Signed-off-by: dependabot[bot] <support@github.com>

Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

requirements.txt

@@ -9,7 +9,7 @@ uwsgi==2.0.19.1
 django-redis==4.12.1
 celery==4.4.7
 
-Pillow==8.0.1
+Pillow==8.1.1
 django-imagekit
 markdown
 django-filter