title: Given a Model enum, how to create a radio button group
body: <p>I have a model like:</p>
  
  <pre><code>class User &lt; ActiveRecord::Base
    enum :status [:banned, :registered, :trial, :pending]
  end
  </code></pre>
  
  <p>On my edit page, I want to show a list of 4 radio buttons and pre-select the radio button that is currently set for a user.</p>
  
  <p>How can I do this?</p>