Adding Matt Robenolt to CONTRIBUTORS

CONTRIBUTORS.txt

@@ -140,4 +140,5 @@ Oleg Anashkin, 2013/06/27
 Ross Lawley, 2013/07/05
 Alain Masiero, 2013/08/07
 Adrien Guinet, 2013/08/14
-Christopher Lee, 2013/08/29
+Christopher Lee, 2013/08/29
+Matt Robenolt, 2013/08/31