NPM version is not up to date

Hey! Thanks for the module but I get a problem, I cant get any callback on audio completion. I realized that there is a diverging between the latest npm version 0.5.0 and your git repository.
In the main file (`play.js`), in the `exit` listener, the case for `... else if (code == 0) { ...` is missing, could you update the package ?

Thanks