supervised genstage, producer, producer_consumer, consumer

setup.ex

		{:ok, p} = Producer.start_link

		workers_num = 20
		workers = Enum.map(1..workers_num, fn (n)-> 
			worker(ProducerConsumer, [worker_name(n)], id: n)
		end)
		worker_names = Enum.map 1..8, &worker_name/1
		
		#consumer subscribes to the producer names passed 
		consumers = [worker(Consumer, [worker_names])]
		
		children = workers ++ consumers
		Supervisor.start_link children, strategy: :rest_for_one