Replaced test urls by ROOT_URLCONF override

@@ -16,13 +16,15 @@ from testapp.models import Article, Author
 CT = ContentType.objects.get_for_model
 
 
-@override_settings(PASSWORD_HASHERS=('django.contrib.auth.hashers.UnsaltedMD5PasswordHasher',))
+@override_settings(
+    PASSWORD_HASHERS=('django.contrib.auth.hashers.UnsaltedMD5PasswordHasher',),
+    ROOT_URLCONF='testapp.urls_default',
+)
 class CommentTestCase(TestCase):
     """
     Helper base class for comment tests that need data.
     """
     fixtures = ["comment_tests"]
-    urls = 'testapp.urls_default'
 
     def createSomeComments(self):
         # Two anonymous comments on two different objects

@@ -50,10 +50,9 @@ class CommentAppAPITests(CommentTestCase):
 
 
 @override_settings(
-    COMMENTS_APP='custom_comments',
+    COMMENTS_APP='custom_comments', ROOT_URLCONF='testapp.urls',
 )
 class CustomCommentTest(CommentTestCase):
-    urls = 'testapp.urls'
 
     def testGetCommentApp(self):
         import custom_comments

@@ -5,6 +5,7 @@ from xml.etree import ElementTree as ET
 from django.conf import settings
 from django.contrib.contenttypes.models import ContentType
 from django.contrib.sites.models import Site
+from django.test.utils import override_settings
 
 from django_comments.models import Comment
 
@@ -12,8 +13,8 @@ from . import CommentTestCase
 from testapp.models import Article
 
 
+@override_settings(ROOT_URLCONF='testapp.urls')
 class CommentFeedTests(CommentTestCase):
-    urls = 'testapp.urls'
     feed_url = '/rss/comments/'
 
     def setUp(self):

@@ -2,6 +2,7 @@ from __future__ import absolute_import, unicode_literals
 
 from django.contrib.auth.models import User, Permission
 from django.contrib.contenttypes.models import ContentType
+from django.test.utils import override_settings
 from django.utils import translation
 
 from django_comments import signals
@@ -259,8 +260,8 @@ class ApproveViewTests(CommentTestCase):
         self.assertTemplateUsed(response, "comments/approved.html")
 
 
+@override_settings(ROOT_URLCONF='testapp.urls_admin')
 class AdminActionsTests(CommentTestCase):
-    urls = "testapp.urls_admin"
 
     def setUp(self):
         super(AdminActionsTests, self).setUp()