Bump requests from 2.21.0 to 2.24.0

Bumps [requests](https://github.com/psf/requests) from 2.21.0 to 2.24.0.
- [Release notes](https://github.com/psf/requests/releases)
- [Changelog](https://github.com/psf/requests/blob/master/HISTORY.md)
- [Commits](psf/requests@v2.21.0...v2.24.0)

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

Author: dependabot-preview[bot]

requirements.txt

@@ -10,6 +10,6 @@ idna==2.8
 opbeat==3.5.2
 psycopg2-binary==2.7.7
 pytz==2018.9
-requests==2.21.0
+requests==2.24.0
 urllib3==1.24.2
 whitenoise==4.1.2