* 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
* 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