fixes scratch_dir not found error

[reijop]

Found a scratch_dir not found error on 10.28. Turns the variable into a node attribute.

[dpetzel]

Ha, I was just trying to get setup with chef-zero to try and reproduce this. I don't think scratch dir needs to be a node attribute. It exists only as workaround to force downloading of files from the server, and it shouldn't ideally hold any prominent position in the cookbook.

The fix I was thinking about was to update def load_tests(scratch_dir) and then load_tests(scratch_dir), or do you think there is value in exposing scratch_dir?

[reijop]

Hey Dave! I was thinking in a pretty primitive fashion when I came up with this.

I like yours better.

I really would only care about any reports that come out of minitest - I can't see a situation for another CB/handler to know about scratch_dir.

[dpetzel]

You wanna amend this PR with another commit if you're already setup to test?

[dpetzel]

I'm having a heck of a time getting my workstation configured properly with chef-zero to test this code path (its not hit with chef-solo). That said this looks just like what I was thinking, so I am going accept this and get a release cut.