Use tempest.lib data_utils

Use the tempest.lib.common version of data_utils, as the tempest.common
one is not supposed to be used by plugins.

Change-Id: I5d727b37d51a0f4bc1096b3b753a1856ee4683c2
diff --git a/designate_tempest_plugin/tests/api/v1/test_domains.py b/designate_tempest_plugin/tests/api/v1/test_domains.py
index eae4086..7fd2909 100644
--- a/designate_tempest_plugin/tests/api/v1/test_domains.py
+++ b/designate_tempest_plugin/tests/api/v1/test_domains.py
@@ -15,7 +15,7 @@
 #    under the License.
 
 import six
-from tempest.common.utils import data_utils
+from tempest.lib.common.utils import data_utils
 from tempest.lib import exceptions as lib_exc
 from tempest import test
 from tempest.lib import decorators
diff --git a/designate_tempest_plugin/tests/api/v1/test_records.py b/designate_tempest_plugin/tests/api/v1/test_records.py
index 473e9c2..ea38fa6 100644
--- a/designate_tempest_plugin/tests/api/v1/test_records.py
+++ b/designate_tempest_plugin/tests/api/v1/test_records.py
@@ -15,7 +15,7 @@
 #    under the License.
 
 import six
-from tempest.common.utils import data_utils
+from tempest.lib.common.utils import data_utils
 from tempest import test
 from tempest.lib import decorators
 
diff --git a/designate_tempest_plugin/tests/api/v1/test_servers.py b/designate_tempest_plugin/tests/api/v1/test_servers.py
index 45f0ca4..3798bf4 100644
--- a/designate_tempest_plugin/tests/api/v1/test_servers.py
+++ b/designate_tempest_plugin/tests/api/v1/test_servers.py
@@ -14,7 +14,7 @@
 #    under the License.
 
 import six
-from tempest.common.utils import data_utils
+from tempest.lib.common.utils import data_utils
 from tempest.lib import exceptions as lib_exc
 from tempest import test
 from tempest import config