cleanup licensing section more

CONTRIBUTING.md

@@ -59,7 +59,7 @@ We only accept issues that are bug reports or feature requests. Bugs must be iso
 
 ## License
 
-Prior to v3.1, Bootstrap was released under Apache 2. As of v3.1, we are now licensed under [MIT](https://github.com/twbs/bootstrap/blob/master/LICENSE). By contributing your code, you agree to license your contribution under the [MIT](https://github.com/twbs/bootstrap/blob/master/LICENSE-MIT) licenses.
+Prior to v3.1.0, Bootstrap was released under the Apache License v2.0. As of v3.1.0, Bootstrap is now licensed under the [MIT license](https://github.com/twbs/bootstrap/blob/master/LICENSE). By contributing your code, you agree to license your contribution under the [MIT license](https://github.com/twbs/bootstrap/blob/master/LICENSE).