test: include component in tap output

Print test name as (for example) "parallel/test-assert".  Tests that are
scraped from the addons documentation are all named test.js, making it
hard to decipher what test is running when only the filename is printed.

Fixes: https://github.com/nodejs/node/issues/6651
PR-URL: https://github.com/nodejs/node/pull/6653


Reviewed-By: James M Snell <jasnell@gmail.com>