update license year

diff --git a/LICENSE.md b/LICENSE.md
index fa77e18e60b5b3742b0fe3ca34a6279f5f60efd0..c8a9d047e0a24eb404f7dd5e4f8dcce7a70f75f0 100644 (file)
--- a/LICENSE.md
+++ b/LICENSE.md
@@ -1,6 +1,6 @@
 The MIT License (MIT)
 
-Copyright (c) 2017 Yihui Xie
+Copyright (c) 2017-2020 Yihui Xie
 
 Permission is hereby granted, free of charge, to any person obtaining a copy of
 this software and associated documentation files (the "Software"), to deal in