Update dox dependency

Hey @redmunds this is the fix for #52 and superseeds #68 

We just need to update the `dox` dependency here to the new branch, we don't really need to change apify for this.

I refactored the previous solution to make it more reusable and consistent. The whole philosophy of `dox` is quite fragile though, and we'll keep seeing this kind of issues, so I've been checking to see if we can move to `esprima` at some point, but I want to keep pushing changes in the meantime ;)

This should fix the last couple of issues you mentioned [here](https://github.com/jbalsas/apify/pull/68#issuecomment-45971615)