[windows] - make configPath test work on windows

I'd like to see this in a custom test helper. `normalizePath` or something perhaps....

That file might be:

```javascript
'use strict';

module.exports = function(inputPath) {
  if (process.platform === 'win32') {
    return inputPath.replace('/', '\');
  } else {
    return inputPath;
  }
};
```