list server addresses operation and unit tests
diff --git a/openstack/compute/v2/servers/urls.go b/openstack/compute/v2/servers/urls.go
index 4bc6586..faa62bd 100644
--- a/openstack/compute/v2/servers/urls.go
+++ b/openstack/compute/v2/servers/urls.go
@@ -37,3 +37,7 @@
 func metadataURL(client *gophercloud.ServiceClient, id string) string {
 	return client.ServiceURL("servers", id, "metadata")
 }
+
+func listAddressesURL(client *gophercloud.ServiceClient, id string) string {
+	return client.ServiceURL("servers", id, "ips")
+}