Adding correct package declarations to other extension files
diff --git a/openstack/networking/v2/extensions/layer3/urls.go b/openstack/networking/v2/extensions/layer3/urls.go
index e69de29..1040241 100755
--- a/openstack/networking/v2/extensions/layer3/urls.go
+++ b/openstack/networking/v2/extensions/layer3/urls.go
@@ -0,0 +1 @@
+package layer3