Update copyright for 2016 in NOTICE.txt

git-svn-id: https://svn.apache.org/repos/asf/commons/proper/digester/trunk@1725427 13f79535-47bb-0310-9956-ffa450edef68
diff --git a/NOTICE.txt b/NOTICE.txt
index cff92a2..19a54a8 100644
--- a/NOTICE.txt
+++ b/NOTICE.txt
@@ -1,5 +1,5 @@
 Apache Commons Digester
-Copyright 2001-2014 The Apache Software Foundation
+Copyright 2001-2016 The Apache Software Foundation
 
 This product includes software developed at
 The Apache Software Foundation (http://www.apache.org/).