Update copyright year in NOTICE
diff --git a/NOTICE.txt b/NOTICE.txt
index ecd619d..01b7b4b 100644
--- a/NOTICE.txt
+++ b/NOTICE.txt
@@ -1,5 +1,5 @@
 Apache Log4j
-Copyright 2016-2017 Apache Software Foundation
+Copyright 2016-2018 Apache Software Foundation
 
 This product includes software developed at
 The Apache Software Foundation (http://www.apache.org/).