Fix import order to comply with import ordering rules.

Fixes pep8 failures TEMPEST N306 and N301.

Change-Id: I87d6ef4058170da73ff64d4e4a4caf43f8a18046
diff --git a/tempest/tests/identity/admin/test_services.py b/tempest/tests/identity/admin/test_services.py
index da697ab..6baa7c2 100644
--- a/tempest/tests/identity/admin/test_services.py
+++ b/tempest/tests/identity/admin/test_services.py
@@ -17,8 +17,8 @@
 
 import nose
 
-from tempest import exceptions
 from tempest.common.utils.data_utils import rand_name
+from tempest import exceptions
 from tempest.tests.identity import base