Combine Publishers

This release brings you Combine publishers for weather request and automatic response decoding. Here's an example:

let someCoordinate = CLLocationCoordinate2D(latitude: 42.989, longitude: -25.128)
let request = WeatherRequest(coordinate: someCoordinate)

let cancellable = request.makePublisher(apiKey: TestSecret.apiKey)

cancellable will be a publisher of type AnyPublisher<OpenWeatherRequest.Output, Error>