* Combine verification and reverification photo submission end-points.
* Combine verification and reverification Backbone models.
* Allow deletion of verification status in Django admin.
* Initial verification from a checkpoint is associated with the checkpoint.
* Fix critical bug in which an invalid link was sent to Software Secure
  for the photo ID image of reverification attempts.

In-course Reverification checkpoint ask for the camera access twice on
Chrome.

ECOM-1739

ECOM-1612