Bump requests from 2.7.0 to 2.20.0

Bumps [requests](https://github.com/psf/requests) from 2.7.0 to 2.20.0.
- [Release notes](https://github.com/psf/requests/releases)
- [Changelog](https://github.com/psf/requests/blob/master/HISTORY.md)
- [Commits](psf/requests@v2.7.0...v2.20.0)

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

requirements.txt

@@ -39,7 +39,7 @@ pycparser==2.20
 PyJWT==1.7.1
 python-openid==2.2.5
 pytz==2020.4
-requests==2.18.3
+requests==2.20.0
 requests-oauthlib==0.8.0
 six==1.15.0
 solid-i18n==1.4.2