Option to output tests as they happen

[jkugler]

During kitchen verify I have some tests that take a while. I would like to be able to see the results of the tests as they happen, instead of having to wait until all the tests are done before I see the results.

To be clear: I'm not asking for a change in default behavior, just an option such as stream_results: true or some such that go in the verifier stanza. Totally understand this would not be ideal for parallel runs.