[COOK-3131] Cluster logic now use Chef search to add nodes

https://tickets.opscode.com/browse/COOK-3131

Hi folks,

I made couple changes to the cookbook and hopefully it helps other folks.

Summary:

- added search logic in the default recipe
- added attributes to enable the search logic (role name is configurable as well)
- added a Vagrantfile to test
- added a Berksfile for depency on `hostsfiles` cookbook

Hopefully, it helps.

Thanks!