I am using the [Composer](http://getcomposer.org/) package [Omnipay](https://github.com/adrianmacneil/omnipay) in my project and I want to add a new class to the package (in my case it is support for a new payment gateway). The naming does not conflict with anything and it follows the same naming and structure conventions as sibling folders. However, when I run `composer update` it deletes my whole folder of changes even though it didn't need to. Is there a way I can tell composer not to delete that directory?