add self to CONTRIBUTORS.txt

CONTRIBUTORS.txt

@@ -155,3 +155,4 @@ Ionel Cristian Mărieș, 2013/12/09
 Antoine Legrand, 2014/01/09
 Pepijn de Vos, 2014/01/15
 Dan McGee, 2014/01/27
+Paul Kilgo, 2014/01/28