Bump pillow from 5.4.1 to 6.0.0

Bumps [pillow](https://github.com/python-pillow/Pillow) from 5.4.1 to 6.0.0.
- [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...6.0.0)

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

requirements.txt

@@ -28,7 +28,7 @@ lxml==4.3.3
 oauthlib==3.0.1
 # olefile==0.46
 # pandas==0.23.4
-Pillow==5.4.1
+Pillow==6.0.0
 psycopg2-binary==2.8.2
 pyIsEmail==1.3.2
 # pyOpenSSL==18.0.0