Release version 1.5.1

Change-Id: Iecb7bfc4092ef3c726c689c129a5ce7cef3e3bc9
diff --git a/VERSION b/VERSION
index ec802c6..26ca594 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-1.5.1-dev
+1.5.1