title: Deprecation warning for save
body: <p>Here is the strange warning I am getting all over my rails server logs</p>
  
  <blockquote>
    <p>DEPRECATION WARNING: The behavior of <code>changed_attributes</code> inside of after callbacks will be changing in the next version of Rails. The new return value will reflect the behavior of calling the method after <code>save</code> returned (e.g. the opposite of what it returns now). To maintain the current behavior, use <code>saved_changes.transform_values(&amp;:first)</code> instead. </p>
  </blockquote>
  
  <p>Here is the code that is causing it</p>
  
  <pre><code>def create_account
    user = User.new(
      first_name: @user_details['first_name'],
      last_name: @user_details['last_name'],
      email: @user_details['email'],
      timezone: @user_details['timezone'],
      locale: @user_details['locale'],
      :remote_avatar_url =&gt; @user_details['picture']['data']['url'].to_s
    )
    if user.save ## this is the line that seems to be in logs
      render json: {
        auth_token: user.auth_token,
        status: 200,
        show_categories_screen: true
      }
    else
      render json: { errors: user.errors.messages, status: 500 }
    end
  end
  </code></pre>
  
  <p>Rails version is 5.1.2</p>