title: change size and maxlength allowed for a field in simple_form
body: <p>How can I change the size and max allowed characters for a field using Simple Forms.  I've tried following but does not work:</p>
  
  <pre><code>&lt;%= f.input :lastname, :size =&gt; 40, :max =&gt; 4 %&gt;
  </code></pre>
  
  <p>I know there is a <code>default_input_size</code> in <code>initializers/simple_form.rb</code> however, I don't want to change the size globally but just on few fields. </p>
  
  <p>How would I do this?</p>