Add delayed_job
Migrate back to delayed_job the app and users_checker workers
Migrate clean accounts scheduler
Migrate clean courses scheduler
Migrate fetch absences worker
Migrate fetch detailed grades worker
Migrate fetch schedule worker
Migrate fetch session worker
Migrate update absences scheduler worker
Migrate update grades scheduler worker
Migrate update schedules scheduler worker
Migrate update sessions scheduler worker
Remove unused worker
Finish configuring delayed_job
Remove resque
Start and stop jobs on deployment