Need to port off of Circle CI 1.0 by August 31st 2018

Created by: langford

Description

Circle CI issues an warning message when doing builds stating the version we use is going to be no longer available after August 30th, 2018

openapi-generator version

All

OpenAPI declaration file content or url

https://github.com/OpenAPITools/openapi-generator/blob/master/circle.yml

Command line used for generation

N/A

Steps to reproduce

Do a build in a PR for this repo

Related issues/PRs

N/A

Suggest a fix/enhancement

Update to latest CI build