[Kotlin][Client] new library support: Retrofit 2.x (!4518) · Merge requests · OpenAPI Tools / openapi-generator

Merged Administrator requested to merge github/fork/javils/feature/kotlin/library/retrofit into master Nov 17, 2019

Created by: javils

PR checklist

Read the contribution guidelines.
If contributing template-only or documentation-only changes which will change sample output, build the project before.
Run the shell script(s) under ./bin/ (or Windows batch scripts under.\bin\windows) to update Petstore samples related to your fix. This is important, as CI jobs will verify all generator outputs of your HEAD commit, and these must match the expectations made by your contribution. You only need to run ./bin/{LANG}-petstore.sh, ./bin/openapi3/{LANG}-petstore.sh if updating the code or mustache templates for a language ({LANG}) (e.g. php, ruby, python, etc).
File the PR against the correct branch: master, 4.3.x, 5.0.x. Default: master.
Copy the technical committee to review the pull request if your PR is targeting a particular programming language.

PR Description

This PR add support for retrofit2 as a HTTP library in kotlin-client generator. The reason to add this feature is that I want to port some old android java code to kotlin, but I couldn't because retrofit2 was not supported.

@jimschubert @dr4ke616 @karismann @Zomzog @andrewemery