[VOL-3665] Update voltha library to the latest

Change-Id: Ieae89b82488379da4b99ab7b7a5356990a8bcdd3
diff --git a/VERSION b/VERSION
index 6a6a3d8..745ec0d 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-2.6.1
+2.6.2-dev