Changes to Add attachment to candidate

added the new required request property attachment

the request's body type changed from no type to object

removed subschema #1 from the request body allOf list

added the new optional request property remote_fields

removed the non-success response with the status 400

removed the non-success response with the status 401

removed the non-success response with the status 403

removed the non-success response with the status 404

removed the non-success response with the status 503

the status response property const value success was added for the status 200

removed the success enum value from the status response property for the response status 200

added the required property warnings to the response with the 200 status