All pr's more than accepted. Create a new runner its quite easy, just following the examples.
If want to add a new runner (behat, phpspec, others..), please follow the examples in the folder src/CodeQualityTool/Checker/
After that, please do a test of the runnner, there is a lot of examples to follow.
Its important, after doing so, you add a config to the commands, Entire, and precommit, and also run by fixtro, so you can test your pr with this same tool.
After that, if everything its ok, please send the pr.
Thanks!!