Bump xos libraries to version 4.0.0

Change-Id: I07891c1f308593cef9b0f456512630eb279cc94f
diff --git a/VERSION b/VERSION
index 456ea72..d72f262 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-1.3.3-dev
+2.0.0-dev