Scheduler demo

This application exposes following endpoints:

• candidates/ - to manage candidate list
• candidate/[id] - to manage particular candidate
• employees/ - to manage candidate list
• employee/[id] - to manage particular candidate
• slots/ - to manage slots
• slot/[id] - to manage particular slot
• slots/candidate_id=[id] - to add slot for candidate
• slots/employee_id=[id] - to add slot for employee
• slots/candidate_id=[id]&employee_ids=[ids] - to get intersection between all slots