Releasing 2.6 VOLTHA helm charts

Change-Id: I99e5cda89cf3c483aa0924cf3c8126af42c2ed95
diff --git a/VERSION b/VERSION
index 9080d9c..e70b452 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-2.5.1-dev
+2.6.0