Using openonu adapter with fixes for ONU SW upgrade

Change-Id: I03a52470d99f06c5669a3abdd173b587c315fe0f
diff --git a/VERSION b/VERSION
index 37c2961..2c9b4ef 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-2.7.2
+2.7.3