app/templates/event/who-are-you.hbs
<h3>Please identify yourself</h3>
<p class="lead">
Your friend {{model.users.firstObject.name}} created an event "{{model.name}}" and wants
to share expenses with you. Please tell us who you are and you will see this event.
</p>
{{#each model.users as |user|}}
<button class="btn btn-default" {{action "chooseUser" user}}>
{{user.name}}
</button>
{{/each}}