User has many sleeps
strong_params for decent_exposure
Basic CRU actions for SleepsController
Add link to new_sleep_path
views/sleeps/new and views/sleeps/_form
Gem database_cleaner added
Fix user factory
Specs for User#usually_gets_up_at and User#usually_goes_to_sleep_at
Add 'recent' scope to Sleep model
Fix typo in User spec
User#average_time and related methods
Gem binding_of_caller added
Fix redirect_to notices in Sleeps controller
User: default values for usually_* methods
Implement usually_* methods in views
User model: validate presence of started_at and finished_at