Bump requests from 2.20.0 to 2.31.0 in /cloudwatchevents/test

Bumps [requests](https://github.com/psf/requests) from 2.20.0 to 2.31.0.
- [Release notes](https://github.com/psf/requests/releases)
- [Changelog](https://github.com/psf/requests/blob/main/HISTORY.md)
- [Commits](psf/requests@v2.20.0...v2.31.0)

---
updated-dependencies:
- dependency-name: requests
  dependency-type: direct:production
...

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

Author: dependabot[bot]

cloudwatchevents/test/requirements.txt

@@ -1,3 +1,3 @@
-requests==2.20.0
+requests==2.31.0
 boto3==1.5.1
 sumologic-sdk==0.1.11