Fixup URL assembly, add simple test
diff --git a/openstack/compute/v2/images/urls.go b/openstack/compute/v2/images/urls.go
index 9b3c86d..b1bf103 100644
--- a/openstack/compute/v2/images/urls.go
+++ b/openstack/compute/v2/images/urls.go
@@ -9,3 +9,7 @@
 func getURL(client *gophercloud.ServiceClient, id string) string {
 	return client.ServiceURL("images", id)
 }
+
+func deleteURL(client *gophercloud.ServiceClient, id string) string {
+	return client.ServiceURL("images", id)
+}