Bump pillow from 5.2.0 to 6.2.2
Bump pillow from 5.2.0 to 6.2.2

Bumps [pillow](https://github.com/python-pillow/Pillow) from 5.2.0 to 6.2.2.
- [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/5.2.0...6.2.2)

Signed-off-by: dependabot[bot] <5bdcd3c0d4d24ae3e71b3b452a024c6324c7e4bb@github.com>
anibali/pywebp,anibali/pywebp,anibali/pywebp