add shebang lines to all lib files

With gerrit 2.8, and the new change screen, this will trigger syntax
highlighting in gerrit. Thus making reviewing code a lot nicer.

Change-Id: Id238748417ffab53e02d59413dba66f61e724383
diff --git a/lib/neutron_plugins/nuage b/lib/neutron_plugins/nuage
index 70de8fa..7bce233 100644
--- a/lib/neutron_plugins/nuage
+++ b/lib/neutron_plugins/nuage
@@ -1,3 +1,5 @@
+#!/bin/bash
+#
 # Nuage Neutron Plugin
 # ----------------------