Load Raven async

gistfile1.js

(function(w){
  if (typeof Raven == 'undefined') {
    w._r = w._r || [];
    w.onerror = function e(msg, url, ln) {
      w._r.push([msg, url, ln]);
    }
  }
})(window)

function loadJS(src, callback) {
  var script = document.createElement('script'),
      loaded;
  script.setAttribute('src', src);
  if (callback) {
    script.onreadystatechange = script.onload = function() {
      if (!loaded) {
        callback();
      }
      loaded = true;
    };
  }
  document.getElementsByTagName('head')[0].appendChild(script);
}

loadJS("//d3nslu0hdya83q.cloudfront.net/dist/1.0/raven.min.js", function() {
  Raven.config('//url').install();
  _r = _r || [];
  for (var i = 0; i < _r.length; i++) {
    Raven.captureMessage('Message: ' + _r[i][0] + ' - URL: ' + _r[i][1] + ' - Line: ' + _r[i][2])
  }
});