Add Django 4.0 support

CHANGELOG.md

@@ -3,6 +3,7 @@
 - Drop support for Python 2.7, 3.5 and 3.6
 - Add support for Python 3.10
 - Drop support for Django 1.11, 2.0, 2.1, 3.0 and 3.1
+- Add support for Django 4.0
 - Fix index creation detection when table is being created in the transaction (issue #178)
 
 ## 3.0.1