Bump django-cas-ng from 5.0.1 to 5.1.0

Bumps [django-cas-ng](https://github.com/django-cas-ng/django-cas-ng) from 5.0.1 to 5.1.0.
- [Release notes](https://github.com/django-cas-ng/django-cas-ng/releases)
- [Changelog](https://github.com/django-cas-ng/django-cas-ng/blob/master/docs/changelog.rst)
- [Commits](django-cas-ng/django-cas-ng@v5.0.1...v5.1.0)

---
updated-dependencies:
- dependency-name: django-cas-ng
  dependency-version: 5.1.0
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

Author: dependabot[bot]

requirements.txt

@@ -52,7 +52,7 @@ botocore>=1.12.198,<1.41.0
 python-dateutil==2.9.0.post0
 
 python-cas==1.6.0
-django-cas-ng==5.0.1
+django-cas-ng==5.1.0
 django-indexer==0.3.0
 # django-templatetag-sugar==1.0
 # django-paging==0.2.5