Upgrade to ZooKeeper 3.4.6

Signed-off-by: Maxime Petazzoni <max@signalfuse.com>
Explicit ZooKeeper node IDs

Signed-off-by: Maxime Petazzoni <max@signalfuse.com>
Merge pull request #4 from signalfuse/node-ids

Explicit ZooKeeper node IDs and upgrade to 3.4.6