Update copyright year.

Author: jenetics

README.md

@@ -141,7 +141,7 @@ The runtime performance of the PRNGs was tested with the [JMH](http://openjdk.ja
 
 The library is licensed under the [Apache License, Version 2.0](http://www.apache.org/licenses/LICENSE-2.0.html).
 
-    Copyright 2017-2018 Franz Wilhelmstötter
+    Copyright 2017-2019 Franz Wilhelmstötter
 
     Licensed under the Apache License, Version 2.0 (the "License");
     you may not use this file except in compliance with the License.