Bump pillow from 8.0.1 to 8.1.1

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](python-pillow/Pillow@8.0.1...8.1.1)

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

Author: dependabot[bot]

requirements.txt

@@ -72,7 +72,7 @@ parso==0.8.1
 pathspec==0.5.9
 pexpect==4.8.0
 pickleshare==0.7.5
-Pillow==8.0.1
+Pillow==8.1.1
 pluggy==0.13.1
 prometheus-client==0.9.0
 prompt-toolkit==3.0.14