title: Redux Form Checkbox Validation
body: <p>I have the following code. The checkbox is for confirming that the user has read Terms and Conditions. Im not sure how to add validation for this on the front end. i.e. If the user clicks submit without checking this box, I want to highlight this text in some way that lets the user know to agree to Terms.</p>
  
  <pre><code>&lt;Field
      label='Terms'
      name="terms-and-conditions"
      type="checkbox"
      component={this.renderField}
      submissionErrors={this.state.submissionErrors}
  /&gt;
  </code></pre>