bump VERSION file for 1.6 development

Change-Id: Iaca40e303d6b45ff57136a3d4ccc10cd41faa20c
diff --git a/VERSION b/VERSION
index 0d4d124..bcfbf47 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-0.1.0-dev
+1.6.0-dev