* [swift] introduce result type as response library
* iOS - run petstore samples
* [swift4] add result sample to testing pipeline
* [swift] update docs with result type
* [swift] update result visibility
* [swift] update docs
* [swift] implement non public api
* [swift] add petstore for non public api
* [swift] fix error in extension that cannot be internal
* [swift] update docs
* Add a swift4 client generator
* Updates per review comments:
- Changed Alamofire dependency from 4.0 to 4.5
- Added "Codable", "Encodable", and "Decodable" to list of reserved words in generator
- Ran "pod update" in default, promisekit, and rxswift samples test projects