VOL-3589 Update voltha go to support new version v4 of voltha protos

Change-Id: I32074b5c05b08f8ebd2205f8dc2af225bff465cc
diff --git a/VERSION b/VERSION
index e70b452..6a6a3d8 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-2.6.0
+2.6.1