Remove queue from zk consumer
To ensure client code has explicit control over the reading of messages
This change removes the ability to listen to multiple topics at once,
as it is not feasible to build this functionality in at the library
level while still giving client code total control and knowledge over
which messages have been read / what the current offset is.
Remove no longer used pipe implementation
Add nrepl-port to gitignore
Up project version to reflect breaking change
Merge pull request #22 from uswitch/unqueued-zk-consumer

Unqueued zk consumer