code: function parseUncssrc(filename) {
      let options = JSON.parse(fs.readFileSync(filename, 'utf-8'));
  
      /* RegExps can't be stored as JSON, therefore we need to parse them manually.
       * A string is a RegExp if it starts with '/', since that wouldn't be a valid CSS selector.
       */
      options.ignore = options.ignore ? options.ignore.map(strToRegExp) : undefined;
      options.ignoreSheets = options.ignoreSheets ? options.ignoreSheets.map(strToRegExp) : undefined;
  
      return options;
  }
docs: Parse a given uncssrc file.
  @param  {String} filename The location of the uncssrc file
  @return {Object}          The options object