Future work:
- improve test coverage (on presenters themselves)
- Look into API versioning, use this representation in HTTP API too in a
  new version
- Delete old formatting code once released.
- Sort out the mess of different reading representations we use in
  different places and radically simplify that part of everything

Move shared code into top level application controller, add Devices#show
and Devices#index using new presentations

…ed to sidekiq are strings

…oint