Include Assignee ID's in project export

Description

When exporting a project the assignee_id is set to nil.

Internal Zendesk Ticket

=> {"id"=>19,
 "title"=>"title issue",
 "assignee_id"=>nil,
 "author_id"=>2,
 "project_id"=>50

Overview

If the ids are included they can be used to reference/map the assignees for backup or migrating data.

For example you could get the exported json file, and then find and replace the old user id’s with the new user id’s before you import it into the new instance, such that no information is lost during the migration.