Bump django from 3.0.5 to 3.0.7 in /example

Bumps [django](https://github.com/django/django) from 3.0.5 to 3.0.7.
- [Release notes](https://github.com/django/django/releases)
- [Commits](django/django@3.0.5...3.0.7)

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

example/requirements.txt

@@ -1,5 +1,5 @@
 # Your app requirements.
 -r ../requirements_test.txt
-django==3.0.5
+django==3.0.7
 # Your app in editable mode.
 -e ../