Bump copyright year

Author: oschwald

README.md

@@ -198,6 +198,6 @@ The MaxMind DB Reader API uses [Semantic Versioning](https://semver.org/).
 
 ## Copyright and License ##
 
-This software is Copyright (c) 2014-2020 by MaxMind, Inc.
+This software is Copyright (c) 2014-2022 by MaxMind, Inc.
 
 This is free software, licensed under the Apache License, Version 2.0.