Added rename directive for composer

When renaming a package, you should add a [`rename`](https://getcomposer.org/doc/04-schema.md#replace) directive. be0974802d9ff19d6b4c12c288b3a4fd5c625415

Current problem: Some packages require twitter/bootstrap while are require twbs/bootstrap, making it impossible to use these package together. See also jasny/bootstrap#254