[REQ] Kotlin Client should support DELETE with body

Created by: oharaandrew314

Is your feature request related to a problem? Please describe.

RFC 7231 allow for the inclusion of a body in a DELETE request, but generated kotlin clients (as seen here) will not send a body.

Describe the solution you'd like

Respect the request body and send it with the delete request.

The following code will fix the line in the generated client.

RequestMethod.DELETE -> Request.Builder().url(url).delete(requestBody(body, contentType))