test: add test configuration templates

Template configuration files for marking tests as flaky.

PR-URL: https://github.com/nodejs/node/pull/2424


Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl>
Reviewed-By: João Reis <reis@janeasystems.com>
Reviewed-By: Sakthipriyan Vairamani <thechargingvolcano@gmail.com>