Update SleepingBarberProblem.py

Implement Sleeping Barber problem using semaphore.
Constraints:
1. There is only 1 barber.
2. The barber can only service 1 customer at a time.
3. Customers have priorities(FIFO).
4. The barber shop waiting lounge can only accomodate a limited number of customers.
5. A customer in the waiting lounge is allowed to leave
6. Because of different hair and styling conditions, the service time varies.

To end the simulation, designate a customer to be the last customer. After the barber services 
this customer, the simulation ends. This is called the poison-pill approach.

Use the logging module to log the simulation.

Do not use the built in Python queue. Implement your own queue.