Bump requests from 2.19.1 to 2.20.0

Bumps [requests](https://github.com/psf/requests) from 2.19.1 to 2.20.0.
- [Release notes](https://github.com/psf/requests/releases)
- [Changelog](https://github.com/psf/requests/blob/master/HISTORY.md)
- [Commits](https://github.com/psf/requests/compare/v2.19.1...v2.20.0)

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

requirements.txt

@@ -6,7 +6,7 @@ idna==2.7
 itsdangerous==0.24
 Jinja2==2.10
 MarkupSafe==1.0
-requests==2.19.1
+requests==2.20.0
 urllib3==1.23
 Werkzeug==0.14.1
 honeycomb-beeline==2.11.4