correction in Queue so it can have infinite capacity
now corrected in globals. Also env is defined there
correction in main script so that it can run for infinite time. Problem that SimPy3 does not set env.now to last event, so reading from the last exit brought back there
Machine/QueueJobshop ported to SimPy3
main script to also initilize the environment so that tests run. TODO now code would no accept multiple runs