Waltz IntegrationHelper should be more generic

[whynick1]

Waltz IntegrationHelper currently makes some assumptions about a cluster setup.

i.e.

this.storageGroupMap = Utils.map(host + ":" + storagePort, STORAGE_GROUP_ID);

ZooKeeperCli.Create.createCluster(zkClient, root, "test cluster", numPartitions);
ZooKeeperCli.Create.createStores(zkClient, root, numPartitions, storageGroupMap);

The helper instance, upon starting ZK, creates znode metadata that implies there is only one storage node. A few other helper methods also assume there is only one waltz server/storage node (i.e. getServerPort(), getStoragePort(), etc.). It should be made more configurable such that the number of server/storage nodes is not presumed.