Update README.rst (#2682)

Author: max-sixty

README.rst

@@ -114,7 +114,7 @@ __ http://climate.com/
 License
 -------
 
-Copyright 2014-2018, xarray Developers
+Copyright 2014-2019, xarray Developers
 
 Licensed under the Apache License, Version 2.0 (the "License");
 you may not use this file except in compliance with the License.