Add ChefSpec matcher

[wndhydrnt]

This adds a matcher for the s3_file provider with create action.
The matcher can be called in a spec like this: create_s3_file.

Official documentation on how to write matchers can be found here.

[wday]

👍

[joekiller]

Can someone confirm that this still works? I'll try to review more closely but my time is limited.

[wndhydrnt]

Hey @joekiller
we're using the ChefSpec matcher to test cookbooks that use the s3_file provider. The cookbooks are not public so I cannot provide a link, but it works for us since July.

Hope that helps. If not, just let me know what you need.

[joekiller]

Okay just wanted to know it was tested.