ES6 modules support

It would be great to be able to do so:

```js
import angular from 'angular';
import uiNavbar from 'ui-navbar';

export const MyModule = angular
  .module('app.my.modyle', [
    uiNavbar
  ])
  .name;
```

Read more about this approach can be found [here](https://github.com/toddmotto/angular-styleguide). 