New option for customizing testPaths

[banacorn]

This commit adds a new option transformTestPaths: [FilePath] -> [FilePath] to createRunner,
which allows users to map the origin given paths ["./spec"] to whatever paths they want.

This is particularly useful when you need to put your test in places other than ./spec/

[Alhadis]

Just use this. I don't think this runner is maintained much anymore.

atom-mocha enables you to use an ordinary .mocharc.js file as a config, so you have full programmatic freedom over what and where test folders or files are loaded from:

https://github.com/Alhadis/Atom-Mocha/blob/master/docs/options.md#tests

[banacorn]

Thanks!