Additional attributes

I'd like to be able to control `zookeper` cluster behavior for the following scenario:
Setup 3 zookeper nodes cluster without having to reconfigure any of them after the other one is provisioned (and searchable).

Thus, I introduced 2 attributes: 
- `search_cluster_servers` attribute determines whether zookeper nodes should be searched (chef server, chef-solo-search). Defaults to true if search is available.
- `auto_add_current_node` attribute determines whether current node should be a part of a cluster. Defaults to true if current node role is `zookeper`

Solution:
1. auto_add_current_node => false
2. search_cluster_servers => false
3. cluster_servers => [1, 2, 3]