Bump requests from 2.19.1 to 2.20.0

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

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

requirements.txt

@@ -1 +1 @@
-requests==2.19.1
+requests==2.20.0