Swift 4, Xcode 9, iOS 11 Support

This release fix some compatibility issue with swift 4, Xcode 9, and iOS 11.

Also looking for a maintainer!

Hero helped me learned a lot about iOS over the last year. Fighting the iOS animation system and dealing with UI bugs has been quite a journey. But I am sorry to say that I do not have to time to maintain this project anymore. The scope of this project has become unmanageable for me to handle. I am looking for a project maintainer to this project and I'm open to transfer this to a public organization instead of under my personal account.

I will still be using Hero in productions, and contribute to critical bug fixes and new iOS release.