add deps for barbican-tempest-plugin

oslo_config and oslo_log are imported in
codes, such as:
https://github.com/openstack/barbican-tempest-plugin
/blob/master/barbican_tempest_plugin/config.py#L16
https://github.com/openstack/barbican-tempest-plugin
/blob/master/barbican_tempest_plugin/tests/scenario/barbican_manager.py#L29
So, we should add them as deps.

Change-Id: Id22657b0169d302bbf62747ef7708d456107c529
diff --git a/test-requirements.txt b/test-requirements.txt
index 74109e4..b879805 100644
--- a/test-requirements.txt
+++ b/test-requirements.txt
@@ -11,3 +11,5 @@
 testrepository>=0.0.18  # Apache-2.0/BSD
 testscenarios>=0.4  # Apache-2.0/BSD
 testtools>=1.4.0 # MIT
+
+oslo.log>=3.22.0 # Apache-2.0