title: How to display a list of users with simple_form?
body: <p>When I do this: <code>&lt;%= f.association :user, :collection =&gt;  User.where(:country_id =&gt; 1) %&gt;</code></p>
  
  <p>My dropdown is populated with lines like this:
  <code>#&lt;User:0x0000010b98d170&gt;</code></p>
  
  <p>Instead, I would like to display an email, that is tied to the id of the users.</p>
  
  <p>I have yet to find how to override the value / content defaults of simple_form when using associations.</p>
  
  <p>Can anyone help?</p>
  
  <p>thank you,
  P.</p>