Releasing voltha-go for voltha-2.6

Change-Id: I6a19fbde5719b97d9cc886f0f9f119099842c5e3
diff --git a/VERSION b/VERSION
index 21f3dae..ec1cf33 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-2.6.3-dev
+2.6.3