Merge pull request #298 from p1c2u/dependabot/pip/django-2.2.18

Bump django from 2.2.13 to 2.2.18

Author: p1c2u

requirements_dev.txt

@@ -4,7 +4,7 @@ pytest-flake8
 pytest-cov==2.5.1
 falcon==2.0.0
 flask
-django==2.2.13; python_version>="3.0"
+django==2.2.18; python_version>="3.0"
 requests==2.22.0
 responses==0.10.12
 webob