title: redux-form v6 show validation error for select field
body: <p>In v6 of redux-form we can show the errors for normal input fields like following</p>
  
  <p>We can create custom renderField like this</p>
  
  <pre><code>const renderField = ({ input, label, type, meta: { touched, error } }) =&gt; (
    &lt;div&gt;
      &lt;label&gt;{label}&lt;/label&gt;
      &lt;div&gt;
        &lt;input {...input} placeholder={label} type={type}/&gt;
        {touched &amp;&amp; error &amp;&amp; &lt;span&gt;{error}&lt;/span&gt;}
      &lt;/div&gt;
    &lt;/div&gt;
  )
  </code></pre>
  
  <p>And in the form, just we can use that custom renderField</p>
  
  <pre><code> &lt;Field name="username" type="text" component={renderField} label="Username"/&gt;
  </code></pre>
  
  <p>Now  i need to know, How we can do this same for select field, and how should we pass dropdown options to this custom renderFields, Any idea to create custom renderField for select ?</p>