Initial email provider
Merge branch 'master' into email-backend

* master: (23 commits)
  Added some doc on conf
  Added some doc
  refactored validation
  Raise NotFound rather than BadRequest
  hard-code rather than string concatenation (!)
  refactoring
  do not check type
  Refactoring validation
  Update/delete followups
  See followups
  Added views for followup
  Refactoring
  Added TODO
  Added relation between alert and push
  Dates to JSON
  cleanup imports
  Moved to ORM for most of what was using the KV store
  Improved readme
  View alert
  Alerts from db
  ...
Added some documentation
Merge pull request #4 from ox-it/email-backend

Email backend