Refactor so that instances.instance_type is now instances.instance_type_id.

Update the Openstack API to return the correct flavor_id.

nova/tests/test_volume.py

@@ -106,7 +106,7 @@ class VolumeTestCase(test.TestCase):
         inst['launch_time'] = '10'
         inst['user_id'] = 'fake'
         inst['project_id'] = 'fake'
-        inst['instance_type'] = 'm1.tiny'
+        inst['instance_type_id'] = '2'  # m1.tiny
         inst['mac_address'] = utils.generate_mac()
         inst['ami_launch_index'] = 0
         instance_id = db.instance_create(self.context, inst)['id']