more fixes for django stubs, first attempt for a plugin

django-stubs/test/__init__.pyi

@@ -2,4 +2,8 @@ from .testcases import (
     TestCase as TestCase,
     TransactionTestCase as TransactionTestCase,
     SimpleTestCase as SimpleTestCase
+)
+
+from .utils import (
+    override_settings as override_settings
 )