Bump requests from 2.21.0 to 2.22.0 (#98)

Bumps [requests](https://github.com/requests/requests) from 2.21.0 to 2.22.0.
- [Release notes](https://github.com/requests/requests/releases)
- [Changelog](https://github.com/kennethreitz/requests/blob/master/HISTORY.md)
- [Commits](https://github.com/requests/requests/compare/v2.21.0...v2.22.0

)

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

requirements.txt

@@ -7,7 +7,7 @@ numpy==1.16.2
 Pillow>=3.4.1
 python-crfsuite==0.9.6
 Pyqtree==1.0.0
-requests==2.21.0
+requests==2.22.0
 sciencebeam-alignment==0.0.2
 sciencebeam-utils==0.0.5
 sklearn-crfsuite==0.3.6