[ruby] use the ruby_installer cb, dependencies attribute
[ruby] several fixes
       - updated graphiti config, new manditory additions
       - unicorn log files
       - rack_env is now an attribute
       - bundle needs to run as root
       - fixed ruby path for metrics update cron job
       - included runit default recipe
Merge pull request #5 from hw-cookbooks/ruby

Use the `ruby_installer` cookbook and many fixes (and a test)