Fixed a couple of failing test cases

tests/expressions/tests.py

@@ -1,6 +1,7 @@
 from __future__ import unicode_literals
 
 from django.core.exceptions import FieldError
+from django.db import transaction
 from django.db.models import F
 from django.test import TestCase
 from django.utils import six
@@ -185,11 +186,12 @@ def test_filter(self):
             "foo",
         )
 
-        self.assertRaises(FieldError,
-            lambda: Company.objects.exclude(
-                ceo__firstname=F('point_of_contact__firstname')
-            ).update(name=F('point_of_contact__lastname'))
-        )
+        with transaction.atomic():
+            self.assertRaises(FieldError,
+                lambda: Company.objects.exclude(
+                    ceo__firstname=F('point_of_contact__firstname')
+                ).update(name=F('point_of_contact__lastname'))
+            )
 
         # F expressions can be used to update attributes on single objects
         test_gmbh = Company.objects.get(name="Test GmbH")

tests/force_insert_update/tests.py

@@ -26,7 +26,8 @@ def test_force_update(self):
         # Try to update something that doesn't have a primary key in the first
         # place.
         c1 = Counter(name="two", value=2)
-        self.assertRaises(ValueError, c1.save, force_update=True)
+        with transaction.atomic():
+            self.assertRaises(ValueError, c1.save, force_update=True)
         c1.save(force_insert=True)
 
         # Won't work because we can't insert a pk of the same value.