Stop Zookeeper from installing on all the nodes

[karthick-rn]

Currently zookeeper is installed & configured on all the nodes, we need to put in a minor fix so that zookeeper tasks only run on the zookeeper group of hosts. This saves a bit of time during deploying muchos and also worker nodes don't need zookeeper configured. I have tested this fix. Let me know for any questions before I proceed with the PR? Thanks

[ctubbsii]

ZooKeeper needs to be installed on all nodes, even if it's not started/running on those nodes, because Accumulo services, which run on all nodes, needs the jar from ZooKeeper's installation.

[karthick-rn]

Thanks for clarifying. In that case we need to fix only the zookeeper log folder from getting created on all worker nodes.

[ctubbsii]

Is there any harm to having the directory there?