added ability to pass option into hosts within group

Your test failed because of missing rake.

$ bundle exec berks install
Using dhcp (2.1.3)
Using dhcp_net_setup (1.0.0) at './test/cookbooks/dhcp_net_setup'
Installing ubuntu (1.1.2) from site: 'http://cookbooks.opscode.com/api/v1/cookbooks'
Installing ruby-helper (0.0.1) from site: 'http://cookbooks.opscode.com/api/v1/cookbooks'
Installing helpers-databags (1.0.0) from site: 'http://cookbooks.opscode.com/api/v1/cookbooks'
Installing apt (2.3.4) from site: 'http://cookbooks.opscode.com/api/v1/cookbooks'
$ bundle rake test:quick
Could not find command "rake".
The command "bundle rake test:quick" exited with 15.
Done. Your build exited with 1.