test: support writing test output to file
test: support writing test output to file

This is a minimal effort to support test output written both to
stdout and file in order to get our buildbots understanding
test output.

PR-URL: https://github.com/iojs/io.js/pull/934
Reviewed-By: Chris Dickinson <38a75c4c4f5646d63b752460df745c5b937b7e58@gmail.com>
Reviewed-By: Ben Noordhuis <59bd0a3ff43b32849b319e645d4798d8a5d1e889@bnoordhuis.nl>

dreamllq/node,dreamllq/node,dreamllq/node,dreamllq/node,dreamllq/node,dreamllq/node,dreamllq/node,dreamllq/node,dreamllq/node