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/bigswitch_floodlight b/lib/neutron_plugins/bigswitch_floodlight
index 9e84f2e..4166131 100644
--- a/lib/neutron_plugins/bigswitch_floodlight
+++ b/lib/neutron_plugins/bigswitch_floodlight
@@ -1,3 +1,5 @@
+#!/bin/bash
+#
 # Neuton Big Switch/FloodLight plugin
 # ------------------------------------