start basic implementation of managed balanced consumer
start basic implementation of managed balanced consumer

not yet certain if this will end up as its own class, but using it as a workspace to figure out the right abstraction

benauthor/pykafka,wikimedia/operations-debs-python-pykafka,wikimedia/operations-debs-python-pykafka,benauthor/pykafka,wikimedia/operations-debs-python-pykafka,benauthor/pykafka