Fix tox command for running tests

Fix the command for running tox tests and add the missing file.

Change-Id: I41b78a1e39b818ed0534a02bc7736a5c461567e8
diff --git a/.testr.conf b/.testr.conf
new file mode 100644
index 0000000..6a52f97
--- /dev/null
+++ b/.testr.conf
@@ -0,0 +1,5 @@
+[DEFAULT]
+test_command=${PYTHON:-python} -m subunit.run discover -s ./barbican_tempest_plugin -t . $LISTOPT $IDOPTION
+
+test_id_option=--load-list $IDFILE
+test_list_option=--list