copyright year update

LICENSE.md

@@ -7,7 +7,7 @@ whose copyright and license statements are reproduced below, all new
 work on the utf8proc library is licensed under the [MIT "expat"
 license](http://opensource.org/licenses/MIT):
 
-*Copyright © 2014-2019 by Steven G. Johnson, Jiahao Chen, Tony Kelman, Jonas Fonseca, and other contributors listed in the git history.*
+*Copyright © 2014-2021 by Steven G. Johnson, Jiahao Chen, Tony Kelman, Jonas Fonseca, and other contributors listed in the git history.*
 
 Permission is hereby granted, free of charge, to any person obtaining a
 copy of this software and associated documentation files (the "Software"),

utf8proc.c

@@ -1,6 +1,6 @@
 /* -*- mode: c; c-basic-offset: 2; tab-width: 2; indent-tabs-mode: nil -*- */
 /*
- *  Copyright (c) 2014-2019 Steven G. Johnson, Jiahao Chen, Peter Colberg, Tony Kelman, Scott P. Jones, and other contributors.
+ *  Copyright (c) 2014-2021 Steven G. Johnson, Jiahao Chen, Peter Colberg, Tony Kelman, Scott P. Jones, and other contributors.
  *  Copyright (c) 2009 Public Software Group e. V., Berlin, Germany
  *
  *  Permission is hereby granted, free of charge, to any person obtaining a

utf8proc.h

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2014-2019 Steven G. Johnson, Jiahao Chen, Peter Colberg, Tony Kelman, Scott P. Jones, and other contributors.
+ * Copyright (c) 2014-2021 Steven G. Johnson, Jiahao Chen, Peter Colberg, Tony Kelman, Scott P. Jones, and other contributors.
  * Copyright (c) 2009 Public Software Group e. V., Berlin, Germany
  *
  * Permission is hereby granted, free of charge, to any person obtaining a