Restful API
tutoriales
https://www.itsolutionstuff.com/post/codeigniter-3-restful-api-tutorialexample.html
https://dev.to/pardip_trivedi/create-a-rest-api-in-codeigniter-with-basic-authentication-1e7f
https://www.desarrollolibre.net/blog/codeigniter/como-crear-una-api-rest-con-codeigniter#.XXGE9XX7TmE
codeigniter-restserver:
https://github.com/chriskacerguis/codeigniter-restserver
https://github.com/ivantcholakov/codeigniter-restserver-test