Move API tests to neutron.test.api

To make api test development simpler, move the tests to
neutron.tests.api.  The neutron.tests.tempest subtree will remain
while work continues to transition the required functionality to
tempest-lib.

Change-Id: Ie90671fbfe2f633e851da82728e152482133fd87
diff --git a/neutron/tests/tempest/common/isolated_creds.py b/neutron/tests/tempest/common/isolated_creds.py
index 5c94289..b4de93b 100644
--- a/neutron/tests/tempest/common/isolated_creds.py
+++ b/neutron/tests/tempest/common/isolated_creds.py
@@ -17,7 +17,7 @@
 from tempest_lib.common.utils import data_utils
 from tempest_lib import exceptions as lib_exc
 
-from neutron.tests.api.contrib import clients
+from neutron.tests.api import clients
 from neutron.tests.tempest.common import cred_provider
 from neutron.tests.tempest import config
 from neutron.tests.tempest import exceptions