Directory check integration

[kindlyseth]

This pull request adds support for the standard directory check integration, http://docs.datadoghq.com/integrations/directory/ .

[statik]

This looks great, I'd love to start using this on several of my datadog installations.

[miketheman]

@kindlyseth Would you consider porting the Kitchen test to a Spec test? See here for an example.

Specs are much "cheaper" to run overall, and validate template renderings just as much as the kitchen tests do. My hope is that we'll port over all existing kitchen tests to specs, and some of the effort has started, so I'd like to not introduce more if possible.

[kindlyseth]

Yep, I'll try to find time early next week.

[kindlyseth]

@miketheman, I think the CircleCI check is not my error. Looks like it might need a version bump that's probably been done on master, but I didn't know if it was worth it to rebase and do a new PR.

[miketheman]

@kindlyseth Thanks! I've rebased and squashed to a single commit here: https://github.com/DataDog/chef-datadog/compare/kindlyops-directory?expand=1

If it passes CI, then it's ripe for merge, and I'll take it from there.

Thanks!

[miketheman]

Thanks!

[kindlyseth]

Thank you!