[VOL-4020]  voltha-lib-go changes for ONU SW upgrade, new Download, Activate,Retrieve APIs

Change-Id: Iaa87a1b74b5f2e25cb0ab43e47f1549683246951
diff --git a/VERSION b/VERSION
index cf78d5b..8089590 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-4.2.4
+4.3.0