Fix consumer stop buying after first product

[CarstenWalther]

The problem was an integer division where a float division was expected in exponential(60.0 / $consumer_per_minute, random_generator).

Other changes are:

• Remove long delay for program output
• The consumer is now stopped and displays an error message if a thread crashes and debugging is enabled
• The list_of_threads (now threads) is now a class variable instead of a global variable. I tried it as instance variable but had problems initializing it.

[Bouncner]

Carsten, can you please update the main repo with the fix?

And what is thebest way to recreate the docker consumer after that?

[CarstenWalther]

Done. Recreate the consumer with: docker-compose rm docker rmi pricewars_consumer The next docker-compose up creates a new consumer