Bump pillow from 5.4.1 to 7.1.0

Bumps [pillow](https://github.com/python-pillow/Pillow) from 5.4.1 to 7.1.0.
- [Release notes](https://github.com/python-pillow/Pillow/releases)
- [Changelog](https://github.com/python-pillow/Pillow/blob/master/CHANGES.rst)
- [Commits](python-pillow/Pillow@5.4.1...7.1.0)

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

requirements.txt

@@ -31,7 +31,7 @@ MarkupSafe==1.1.0
 mccabe==0.6.1
 passlib==1.7.1
 pep8==1.7.1
-Pillow==5.4.1
+Pillow==7.1.0
 pycparser==2.19
 PyMySQL==0.9.3
 python-dateutil==2.7.5