title: Build select date and year inputs with simple_form
body: <p>In my Ruby on Rails application I have some form that needs inputs to select month and year. I do this with built in Rails select_date input:</p>
  
  <pre><code> = select_date @date, :order =&gt; [ :month, :year], :discard_day =&gt; true
  </code></pre>
  
  <p>But now I want to know is there any way to the same easy with simple_form?</p>