Update README.rst

Author: davesque

README.rst

@@ -22,7 +22,7 @@ Requirements
 ------------
 
 * Python (3.5, 3.6, 3.7)
-* Django (1.11, 2.0, 2.1)
+* Django (1.11, 2.0, 2.1, 2.2)
 * Django REST Framework (3.5, 3.6, 3.7, 3.8, 3.9)
 
 These are the officially supported python and package versions.  Other versions