add index directive
Merge pull request #17 from Apathetic012/master

renamed app_error_path to error_log_path
Compatible with chef > v10.18
Using the new default_action method
Arrays are more appropriate, you should not be caring about the name of
the app. Let me demonstrate:

configs[:nginx][:apps] = [app1, app2]

vs

configs[:nginx][:apps] = {
  :app1 => {...},
  :app2 => {...},
}
Merge branch 'array-vs-hash' of https://github.com/gchef/nginx-cookbook into develop