Replaces uuid.uuid4 with uuidutils.generate_uuid()

Change-Id: I38740842402841ae446603faacbbe969854f2396
Closes-Bug: #1082248

watcher/tests/db/test_purge.py

@@ -14,7 +14,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-import uuid
+from oslo_utils import uuidutils
 
 import freezegun
 import mock
@@ -73,7 +73,7 @@ class TestPurgeCommand(base.DbTestCase):
             seed += 1
 
     def generate_unique_name(self, prefix):
-        return "%s%s" % (prefix, uuid.uuid4())
+        return "%s%s" % (prefix, uuidutils.generate_uuid())
 
     def _data_setup(self):
         # All the 1's are soft_deleted and are expired