prevent integration tests from starting before zookeeper cluster and kafka broker are ready

[tkaemming]

probably could achieve by sending offsets requests until the we get a valid response from the socket

Traceback (most recent call last):
  File "/usr/local/pypy/lib-python/2.7/threading.py", line 552, in __bootstrap_inner
    self.run()
  File "/usr/local/pypy/lib-python/2.7/threading.py", line 505, in run
    self.__target(*self.__args, **self.__kwargs)
  File "/home/travis/builds/disqus/samsa/samsa/consumer/partitions.py", line 128, in _fetch
    size
  File "/home/travis/builds/disqus/samsa/samsa/partitions.py", line 227, in fetch
    return self.broker.client.fetch(self.topic.name, self.number, offset,
  File "/home/travis/builds/disqus/samsa/samsa/brokers.py", line 186, in client
    port=self.port)
  File "/home/travis/builds/disqus/samsa/samsa/client.py", line 396, in __init__
    self.connect()
  File "/home/travis/builds/disqus/samsa/samsa/client.py", line 399, in connect
    self.connection.connect()
  File "/home/travis/builds/disqus/samsa/samsa/client.py", line 334, in connect
    timeout=self.timeout
  File "/usr/local/pypy/lib-python/2.7/socket.py", line 616, in create_connection
    raise err
error: [Errno 111] Connection refused

FAIL
Test that we can consume messages from kafka. ... Exception in thread Thread-141:
Traceback (most recent call last):
  File "/usr/local/pypy/lib-python/2.7/threading.py", line 552, in __bootstrap_inner
    self.run()
  File "/usr/local/pypy/lib-python/2.7/threading.py", line 505, in run
    self.__target(*self.__args, **self.__kwargs)
  File "/home/travis/builds/disqus/samsa/samsa/consumer/partitions.py", line 128, in _fetch
    size
  File "/home/travis/builds/disqus/samsa/samsa/partitions.py", line 228, in fetch
    size)
  File "/home/travis/builds/disqus/samsa/samsa/client.py", line 489, in fetch
    return decode_messages(response.get(), from_offset=offset)
  File "/home/travis/builds/disqus/samsa/samsa/handlers.py", line 50, in get
    raise self.error
error: [Errno 104] Connection reset by peer

[kbourgoin]

Fixed in 0.3.6