Update to latest voltha-go dependency

Change-Id: I623d0e7946a1df7252e98d0fccceb1f9c3f6bd72
diff --git a/VERSION b/VERSION
index 7ec1d6d..3e3c2f1 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-2.1.0
+2.1.1