Adds initial basic workflow.
Adds interview model.
Adds InterviewsController with a single view, create_request.
Change InterviewsController method name from create_request to new (to be more consistent with REST convention).
Minimal UI for new interview view.
Adds minimal versions of the create and show actions.
Adds recruiter_key generation, as well as a confirm_creation action for the recruiter.  Next steps: send the confirm_creation link to the recruiters email address.