* update versions of dependencies on swift4 and swift3
* change syntax for swift4
* run petstore script
* change enum case from UpperCamel to lowerCamel
* remove unneeded break statements
* avoid wrapping conditionals in parentheses
* avoid force casting
* run pod update on petstore/swift4/rxswift
* update project for swift 4
* run swift4-petstore-all.sh
* fix compile error
* avoid use iso8601 date strategy for encoder / decoder
* resolve file references
* Fix build error in Xcode 9 beta 3, as .compact is no longer defined
* Add test schema for Swift 4 and associated script and config files
* Add test app for swift4Test.json schema
* Make integer, Integer, int, and Int32 types map to Swift Int type instead of Int32 type
* Add CodingKeys to model template, which allows us to serialize/deserialize variable names that are different than property names
* Make updates to Swift 4 test schema
* Fixes for unit test app for swift4Test.json Swift 4 test schema
* 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
