Relese xos 4.0.0

Change-Id: I2ab7a061932108f2c4432744ac4855cceba2b5f3
diff --git a/VERSION b/VERSION
index d9b058f..fcdb2e1 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-4.0.0-dev
+4.0.0