Bump the copyright years

Author: bbatsov

LICENSE

@@ -653,7 +653,7 @@ Also add information on how to contact you by electronic and paper mail.
 notice like this when it starts in an interactive mode:
 
     Copyright © 2012-2014 Magnar Sveen
-    Copyright © 2014-2020 Magnar Sveen, Lars Andersen, Benedek Fazekas, Bozhidar Batsov
+    Copyright © 2014-2021 Magnar Sveen, Lars Andersen, Benedek Fazekas, Bozhidar Batsov
 
     Author: Magnar Sveen <magnars@gmail.com>
         Lars Andersen <expez@expez.com>

README.md

@@ -146,7 +146,7 @@ Thanks to [everyone](https://github.com/clojure-emacs/clj-refactor.el/graphs/con
 ## License
 
 Copyright © 2012-2014 Magnar Sveen
-Copyright © 2014-2020 Magnar Sveen, Lars Andersen, Benedek Fazekas, Bozhidar Batsov
+Copyright © 2014-2021 Magnar Sveen, Lars Andersen, Benedek Fazekas, Bozhidar Batsov
 
 Author: Magnar Sveen <magnars@gmail.com>
         Lars Andersen <expez@expez.com>

clj-refactor.el

@@ -1,7 +1,7 @@
 ;;; clj-refactor.el --- A collection of commands for refactoring Clojure code -*- lexical-binding: t -*-
 
 ;; Copyright © 2012-2014 Magnar Sveen
-;; Copyright © 2014-2020 Magnar Sveen, Lars Andersen, Benedek Fazekas, Bozhidar Batsov
+;; Copyright © 2014-2021 Magnar Sveen, Lars Andersen, Benedek Fazekas, Bozhidar Batsov
 
 ;; Author: Magnar Sveen <magnars@gmail.com>
 ;;         Lars Andersen <expez@expez.com>