Update README.md

Author: ramalho

18-context-mngr/lispy/README.md

@@ -22,3 +22,5 @@ and separate tests for each expression and special form handled by `evaluate`.
 `lis.py` is published in the [norvig/pytudes](https://github.com/norvig/pytudes) repository on Github.
 The copyright holder is Peter Norvig and the code is licensed under the
 [MIT license](https://github.com/norvig/pytudes/blob/60168bce8cdfacf57c92a5b2979f0b2e95367753/LICENSE).
+
+Luciano Ramalho wrote the changes and additions described above.