voltha-2.3 release - update ofagent-go version to 1.1.7 and voltha chart version to 2.3.2

Change-Id: If79c6b49d105ffd3c2b175a59b1c07245a3089e1
diff --git a/VERSION b/VERSION
index 32d1656..2bf1c1c 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-2.3.1-dev
+2.3.1