Adding auth0Widget

Hi @ewelton,

You can fetch the dependency without having to put an `<script>` tag, as shown in this Pull Request. `Auth0Widget` needs to be declared global so auth0-angular can create an instance from that class. I'll let you know if this behavior changes in the future (See https://github.com/auth0/auth0-angular/issues/12)

Let me know if that works for you or if I can help you with anything else.

Thanks in advance,