Update photo rest api

This updates the photo api to hit against the mongo database

API implemented:
list: GET  /api/v2/photo
  - List all photos (paging size 20)
  - optional url params
     - sort_by - any of the field names.  Default: 'upload_time'
     - order - ['asc', 'desc'] Default: 'asc'
     - page - page number (0 base). Default: 0
show: GET /api/v2/photo/:id
  - displays the metadata information for photo with the id
update: PATCH /api/v2/photo/:id
  - Updates the photo metadata.
  - Currently only the field, 'original_filename' can be updated
update: DELETE /api/v2/photo/:id
  - Removes a photo from the database, also removes it from the disk