Bump django from 2.0.5 to 2.2.13 in /maps-django-mapbox/djmaps

Bumps [django](https://github.com/django/django) from 2.0.5 to 2.2.13.
- [Release notes](https://github.com/django/django/releases)
- [Commits](django/django@2.0.5...2.2.13)

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

Author: dependabot[bot]

maps-django-mapbox/djmaps/requirements.txt

@@ -1 +1 @@
-django==2.0.5
+django==2.2.13