Blog post on integrating a login modal into Angular apps

Review review review!!!
Why doesn't this just return a promise?

```javascript
app.service("requestAuthentication", function ($modal) {

  return function() {
    $modal.open({
      templateUrl: 'views/loginModalTemplate.html',
      controller: 'LoginModalCtrl',
      controllerAs: 'LoginModalCtrl'
    });
  };

});

// ...

app.run(function ($rootScope, $state, loginModal) {

  $rootScope.$on('$stateChangeStart', function (event, toState, toParams) {
    var requireLogin = toState.data.requireLogin;

    if (requireLogin && typeof $rootScope.currentUser === 'undefined') {
      event.preventDefault();

      requestAuthentication.then(
        function () { return $state.go(toState.name, toParams); },
        function () { return $state.go('welcome'); }
      );
    }
  });

});

// ...
```