[VOL-3960] Adding VOLTHA 2.7 release notes alongside PM counters update and ONU SW update.

Change-Id: I37a99f566b63c7315458fce152481ff471a78879
diff --git a/VERSION b/VERSION
index 1968691..1effb00 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-2.7-dev
+2.7