Merge pull request #128 from tell-k/fix-setup-auth-class

Do not insert  WebtestAuthentication to the head of DEFAULT_AUTHENTICATION_CLASSES.

django_webtest/__init__.py

@@ -301,7 +301,7 @@ def _setup_auth_class(self):
         if class_name not in classes:
             if isinstance(classes, tuple):
                 classes = list(classes)
-            classes.insert(0, class_name)
+            classes.append(class_name)
             drf_settings['DEFAULT_AUTHENTICATION_CLASSES'] = classes
 
     @property