Bump pillow from 6.1.0 to 6.2.0 (#98)

Bumps [pillow](https://github.com/python-pillow/Pillow) from 6.1.0 to 6.2.0.
- [Release notes](https://github.com/python-pillow/Pillow/releases)
- [Changelog](https://github.com/python-pillow/Pillow/blob/master/CHANGES.rst)
- [Commits](python-pillow/Pillow@6.1.0...6.2.0)

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

requirements.txt

@@ -13,4 +13,4 @@ xml4h==0.2.0
 python-magic==0.4.15
 defusedxml==0.6.0
 Flask-Migrate==2.5.2
-pillow==6.1.0
+pillow==6.2.0