[Security] Bump django from 1.11.21 to 1.11.22

Bumps [django](https://github.com/django/django) from 1.11.21 to 1.11.22. **This update includes security fixes.**
- [Release notes](https://github.com/django/django/releases)
- [Commits](django/django@1.11.21...1.11.22)

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

requirements.txt

@@ -2,7 +2,7 @@
 Pillow==6.0.0
 lxml==4.3.3
 psycopg2==2.8.3
-Django==1.11.21
+Django==1.11.22
 
 # Other
 amqp==2.4.2