Bump django-extensions from 2.1.4 to 2.1.5

Bumps [django-extensions](https://github.com/django-extensions/django-extensions) from 2.1.4 to 2.1.5.
- [Release notes](https://github.com/django-extensions/django-extensions/releases)
- [Changelog](https://github.com/django-extensions/django-extensions/blob/master/CHANGELOG.md)
- [Commits](django-extensions/django-extensions@2.1.4...2.1.5)

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

Author: dependabot-support

requirements.txt

@@ -10,7 +10,7 @@ coreapi==2.3.3
 coreschema==0.0.4
 cryptography==2.5
 Django==2.1.5
-django-extensions==2.1.4
+django-extensions==2.1.5
 django-filter==2.1.0
 django-rest-swagger==2.2.0
 djangorestframework==3.9.1