Bump django from 1.11.20 to 1.11.22

Bumps [django](https://github.com/django/django) from 1.11.20 to 1.11.22.
- [Release notes](https://github.com/django/django/releases)
- [Commits](django/django@1.11.20...1.11.22)

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

requirements.txt

@@ -1,4 +1,4 @@
-Django==1.11.20
+Django==1.11.22
 decorator==4.1.2
 bootstrap-admin==0.4.*
 django-debug-toolbar==1.8