Bump django from 2.2.24 to 2.2.28

Bumps [django](https://github.com/django/django) from 2.2.24 to 2.2.28.
- [Release notes](https://github.com/django/django/releases)
- [Commits](django/django@2.2.24...2.2.28)

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

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

setup.py

@@ -25,7 +25,7 @@
     include_package_data=True,
     install_requires=[
         'boto3',
-        'Django==2.2.24',
+        'Django==2.2.28',
         'django-admin-sortable2',
         'django-cors-headers',
         'django-extensions',