aggregate coverage metrics of unit tests across packages (#115)

aggregate coverage metrics of unit tests across packages
diff --git a/openstack/db/v1/instances/testing/doc.go b/openstack/db/v1/instances/testing/doc.go
index 7603f83..386ac58 100644
--- a/openstack/db/v1/instances/testing/doc.go
+++ b/openstack/db/v1/instances/testing/doc.go
@@ -1 +1,2 @@
+// db_instances_v1
 package testing