Fix indentation in clean utility

utils.clean extracts a test method content re-indenting the function for whitespaces.
This commit fixes to issues with indentation

* windows line feed `\r\n`
* tab indentation `\t`
Merge pull request #761 from piuccio/utils_clean

Fix indentation in clean utility

* piuccio/utils_clean:
  Fix indentation in clean utility

Conflicts:
	lib/utils.js