Bump django from 3.1.9 to 3.1.13

Bumps [django](https://github.com/django/django) from 3.1.9 to 3.1.13.
- [Release notes](https://github.com/django/django/releases)
- [Commits](django/django@3.1.9...3.1.13)

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

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

Author: dependabot[bot]

Pipfile

@@ -6,7 +6,7 @@ verify_ssl = true
 [dev-packages]
 
 [packages]
-django = "==3.1.9"
+django = "==3.1.13"
 djangorestframework = "*"
 
 [requires]