Add carthage support

[DevAndArtist]

Hello there, I've been looking for simple Pokémon Go api on github which I can rip off or use a small portion of it as one of my applications layers. Personally I only need something that returns me some meta data about a specific location and that's it. Building a search algorithm is something that the app must do, not the api.

I might have found this here.

---

I'm not a fan of pods because they can become complicated and can break your project if you're not an experienced user.

That's why I'd wish this project here should support both pods and Carthage. 😄

[lsapan]

Well, arguably the search algorithm is something that can be implemented in the library because it is something that would be widely used. Having a central code base for it would only improve it for everyone. That's a separate issue though 😄

As far as Carthage, I've actually never used it! CocoaPods is much more stable now if you want to give that a shot, but I'm more than open to a PR adding Carthage support!