Fixed flake8 warnings.

tests/introspection/tests.py

@@ -130,7 +130,7 @@ class IntrospectionTests(TestCase):
         self.assertEqual(
             set(key_columns),
             {('reporter_id', Reporter._meta.db_table, 'id'),
-                 ('response_to_id', Article._meta.db_table, 'id')})
+             ('response_to_id', Article._meta.db_table, 'id')})
 
     def test_get_primary_key_column(self):
         with connection.cursor() as cursor:

tests/prefetch_related/tests.py

@@ -720,7 +720,7 @@ class GenericRelationTests(TestCase):
             # attributes, so the following makes sense:
             qs = TaggedItem.objects.filter(content_type=ct, tag='awesome').prefetch_related('content_object__read_by')
             readers_of_awesome_books = {r.name for tag in qs
-                                            for r in tag.content_object.read_by.all()}
+                                        for r in tag.content_object.read_by.all()}
             self.assertEqual(readers_of_awesome_books, {"me", "you", "someone"})
 
     def test_nullable_GFK(self):

tests/test_client_regress/tests.py

@@ -994,7 +994,7 @@ class ContextTests(TestCase):
         # None, True and False are builtins of BaseContext, and present
         # in every Context without needing to be added.
         self.assertEqual({'None', 'True', 'False', 'hello', 'goodbye',
-                              'python', 'dolly'},
+                          'python', 'dolly'},
                          l.keys())
 
     def test_15368(self):