Modify to Player::authorize return the Player object.
Add score registration form.
Add Season model.
Fix column name Season#end -> expiry, and (start|end)'s type.
Add Season#range
60 * 60 * 24 is tomorrow
Add Season.for method.
Change seasons to reference Season model
Add admin pages for Seasons.
Fix form for seasons.
Fix to create seasons successfully.
Add validations for Season model.
Add error handling on parsing times.
Fix association about season.
Fix music views/forms in admin page.
Add database_cleaner.
Rename Machine#current_musics -> musics_for.
Fix spec for Machine#musics_for.
Fix easy miss ;(
Fix specs because of using Season model.