Allow Packages To Have Custom Public Paths

[apeacock1991]

Description

Currently the public folder is hard-coded as app/public, which may not work for all users of the gem. They may wish to define their own public folder, and if none is defined, default to app/public.

Why?

Depending on the architecture of the application, app/public might just not make sense, or at least not be cohesive with the rest of the folder structure. Consider a layered architecture for example, where you break up the layers of your application via technical partition (i.e. presentation layer, domain layer, infrastructure layer etc.). Your top-level folders in your package would typically be /presentation, /domain etc., so logically in that architecture you would want to select the layer that makes sense to expose the package from, and app/public conflicts with that vision.

I've raised a PR here that I believe introduces that feature, and seems to work nicely.

[wildmaples]

This feature request as been merged in #37