Adding DeleteResult for v3.services.Delete
diff --git a/openstack/identity/v3/services/requests.go b/openstack/identity/v3/services/requests.go
index 425a67c..bf027e8 100644
--- a/openstack/identity/v3/services/requests.go
+++ b/openstack/identity/v3/services/requests.go
@@ -89,10 +89,11 @@
 
 // Delete removes an existing service.
 // It either deletes all associated endpoints, or fails until all endpoints are deleted.
-func Delete(client *gophercloud.ServiceClient, serviceID string) error {
-	_, err := perigee.Request("DELETE", serviceURL(client, serviceID), perigee.Options{
+func Delete(client *gophercloud.ServiceClient, serviceID string) DeleteResult {
+	var res DeleteResult
+	_, res.Err = perigee.Request("DELETE", serviceURL(client, serviceID), perigee.Options{
 		MoreHeaders: client.AuthenticatedHeaders(),
 		OkCodes:     []int{204},
 	})
-	return err
+	return res
 }