Bump python-dateutil from 2.8.0 to 2.8.1

Bumps [python-dateutil](https://github.com/dateutil/dateutil) from 2.8.0 to 2.8.1.
- [Release notes](https://github.com/dateutil/dateutil/releases)
- [Changelog](https://github.com/dateutil/dateutil/blob/master/NEWS)
- [Commits](dateutil/dateutil@2.8.0...2.8.1)

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

Author: dependabot-preview[bot]

requirements.txt

@@ -25,6 +25,6 @@ itsdangerous==1.1.0
 jsmin==2.2.2
 psycopg2==2.8.3
 pytest==5.1.2
-python-dateutil==2.8.0
+python-dateutil==2.8.1
 redis==3.3.8
 requests==2.22.0