Updated validation tests

Use shoulda-matchers for validations tests
Merge branch 'respond_with' of github.com:peepoltv/peepoltv-api into respond_with

* 'respond_with' of github.com:peepoltv/peepoltv-api:
  Creates a BaseController and moves the API behind /api
  Move API controllers to controllers/api
Moved sessions and registrations to api module
Updated to Devise 3.0
Updated routing specs
Updated registration controller
Updated tags controller
Updated sessions specs
Added authentication to base api controller
Updated Guardfile to watch api directory
Added stream relation to users
Updated user spec
Updated channel to use base api
Updated users controller to use API
Updated stream specs