title: How to add extra fields to django-registration-redux
body: <p>I am trying to add extra fields to django-registration-redux but cannot seem to get it working, I have seen this question has been asked before but it has only been asked for django-registration not django-registration-redux which is different. If someone could please direct me as to what to do that would be great. So far I am defined a model and form as you can see below. Any help appreciated, thanks!</p>
  
  <p>P.S. My model is being registered in the admin page however it will not show up on the register page.</p>
  
  <p>Model -</p>
  
  <pre><code>from django.db import models
  from django.contrib.auth.models import User
  
  class EmployerProfile(models.Model):
  
  user = models.OneToOneField(User, unique=True)
  home_number = models.IntegerField(max_length=12)
  mobile_number = models.IntegerField(max_length=12)
  business_name = models.CharField(max_length=50)
  business_address_number = models.IntegerField()
  business_address_street = models.CharField(max_length=50)
  business_address_region = models.CharField(max_length=50)
  business_address_suburb = models.CharField(max_length=50)
  business_address_postcode = models.IntegerField()
  business_industry = models.CharField(max_length=50)
  
  def __unicode__(self):
      return self.business_name
  </code></pre>
  
  <p>Form - </p>
  
  <pre><code>from django import forms
  from registration.forms import RegistrationForm
  
  class EmployerForm(RegistrationForm):
  
  region_choice = (
      ('1', 'Auckland'),
      ('2', 'Wellington'),
      ('3', 'Christchurch')
  )
  suburb_choice = (
      ('1', 'Glendowie'),
      ('2', 'Kohimarama'),
      ('3', 'Mission Bay')
  )
  industry_choice = (
      ('1', 'Restaurant'),
      ('2', 'IT'),
      ('3', 'Construction')
  )
  
  home_number = forms.IntegerField()
  mobile_number = forms.IntegerField()
  business_name = forms.CharField()
  business_address_number = forms.IntegerField()
  business_address_street = forms.CharField()
  business_address_region = forms.ChoiceField(choices=region_choice)
  business_address_suburb = forms.ChoiceField(choices=suburb_choice)
  business_address_postcode = forms.IntegerField()
  business_industry = forms.ChoiceField(choices=industry_choice)
  </code></pre>