add session test
add retrospective model
add retrospective user model
add label model
add association
add acts_as_list
use acs_as_list to label
add user manage method to retrospective
set I18n.enforce_available_locales
add websocket-rails
setup websocket-rails
fix webcoket-rails test setting
add Ws::RetrospectivesController
add Ws::LabelsController