new license in the README file (#189)

New license in the README file.

README.md

@@ -42,7 +42,7 @@ The package API for yaml v2 will remain stable as described in [gopkg.in](https:
 License
 -------
 
-The yaml package is licensed under the LGPL with an exception that allows it to be linked statically. Please see the LICENSE file for details.
+The yaml package is licensed under the Apache License 2.0. Please see the LICENSE file for details.
 
 
 Example