Add missing parentheses.
Add some more parentheses.
Add dump.rdb to .gitignore.
Move test worker classes into fixtures directory.
Don't use intervals in ScheduledWorker.
Move LastAndScheduledTicksWorker into fixtures.
Add Sidetiq.schedules.
Add Sidetiq.workers.
Add Sidetiq.scheduled.
Add Sidetiq.retries.
Update CHANGELOG.