title: redux-form fields not rerendering/updating after form loads
body: <p>I'm having an issue getting my signin form field validation to work with redux-form. For the moment, I'm just trying to get sync validation to work so I can check for basic errors. The problem is that the form appears to only check validation when the component mounts, then not again after that point. Here's the code I have:</p>
  
  <p><div class="snippet" data-lang="js" data-hide="false" data-console="true" data-babel="false">
  <div class="snippet-code">
  <pre class="snippet-code-js lang-js prettyprint-override"><code>import React from 'react';
  import { Field, reduxForm } from 'redux-form';
  import * as Redux from 'react-redux';
  
  import Input from './../../helpers/Input';
  import Button from './../../helpers/Button';
  
  export const Signup = React.createClass({
  
      renderInput({ label, type, input: { value }, meta: { touched, error }}){
          return (
              &lt;Input label={ label }
                     type={ type }
                     filled={ value ? true : false }
                     touched={ touched }
                     error={ error } /&gt;
          );
      },
  
      render(){
  
          const { handleSubmit } = this.props;
  
          return(
              &lt;div&gt;
                  &lt;form onSubmit={ handleSubmit }&gt;
                      &lt;Field name="email" label="Email" component={ this.renderInput } /&gt;
                      &lt;Field name="username" label="Username" component={ this.renderInput } /&gt;
                      &lt;Field name="password" label="Password" type="password" component={ this.renderInput } /&gt;
                      &lt;Field name="confirmPassword" label="Confirm Password" type="password" component={ this.renderInput } /&gt;
                      &lt;Button type="submit" btnType="main" btnIcon="" btnText="Create Account" /&gt;
                  &lt;/form&gt;
              &lt;/div&gt;
          );
      }
  });
  
  export const validate = values =&gt; {
      const errors = {};
        if (!values.username) {
            errors.username = 'Required';
        } else if (values.username.length &gt; 15) {
            errors.username = 'Must be 15 characters or less';
        }
  
        if (!values.email) {
            errors.email = 'Required';
        } else if (!/^[A-Z0-9._%+-]+@[A-Z0-9.-]+\.[A-Z]{2,4}$/i.test(values.email)) {
            errors.email = 'Invalid email address';
        }
        console.log(errors);
        return errors;
  };
  
  export default reduxForm({
    form: 'signup',
    validate
  })(Signup);</code></pre>
  </div>
  </div>
  </p>
  
  <p>I sense that I'm missing something very fundamental here, but I'm stumped. I feel like an action should be dispatched to toggle the "touched" property onBlur (and thereby rerendering the form), but it doesn't seem to be doing that and I couldn't find anything like that reading through the redux-form docs. Any ideas?</p>