The following were added:
* Images.ListDistribution() for GET /v2/images?type=distribution
* Images.ListApplication() for GET /v2/images?type=application
* Images.ListUser() for GET /v2/images?private=true
* Images.GetByID() for GET /v2/images/12345
* Images.GetBySlug() for GET /v2/images/ubuntu
* Images.Update() for PUT /v2/images/12345
* Images.Delete() for DELETE /v2/images/12345