I would change the `addStyle` function to this:

```js
addStyle: function(src, styles, minify) {
    return styles.reduce(function(result, file) {
      var css = fs.readFileSync(file).toString();

      result.concatenatedCss += css + '\n';
      result.js += processCSS(css, minify);

      return result;
    }, {js: src, concatenatedCss: ''});

    function processCSS(css, minify) {
      // minify
      css = css
          .replace(/\r?\n/g, '')
          .replace(/\/\*.*?\*\//g, '')
          .replace(/:\s+/g, ':')
          .replace(/\s*\{\s*/g, '{')
          .replace(/\s*\}\s*/g, '}')
          .replace(/\s*\,\s*/g, ',')
          .replace(/\s*\;\s*/g, ';');

      // escape for JS
      css = css
        .replace(/\\/g, '\\\\')
        .replace(/'/g, "\\'")
        .replace(/\r?\n/g, '\\n');

      return "if (!document.securityPolicy || !document.securityPolicy.isActive) { angular.element(document).find('head').prepend('<style type=\"text/css\">" + css + "</style>'); }";
    }
  },
```