Changes to Create client

added the non-success response with the status 406

added the non-success response with the status 413

added the non-success response with the status 415

media type application/json was changed to a more specific media type application/vnd.api+json for the response status 201

media type application/json was changed to a more specific media type application/vnd.api+json for the response status 400

media type application/json was changed to a more specific media type application/vnd.api+json for the response status 401

media type application/json was changed to a more specific media type application/vnd.api+json for the response status 403

media type application/json was changed to a more specific media type application/vnd.api+json for the response status 422