Add a SkunkScore for dependencies

[dividedharmony]

The complexity and smell of an application is not just limited to just the project's code. It also includes all the dependencies of that code.

Ideally, there should be a separate score for dependencies so that developers can see which ones they should either eliminate, bring into their own codebase, or (in the case of opensource dependencies) help the maintainers improve those libraries.

[etagwerker]

@dividedharmony good idea! 👍