from django.db import models
from django.contrib.auth.models import User

class MyUser(models.Model):
    user = models.OneToOneField(User, on_delete=models.CASCADE)
    date_of_birth = models.DateField()

class UserProfileRegistration(RegistrationView):
    success_url = '/'
    form_class = UserProfileRegistrationForm

    def register(self, form):
        """
        Implement user-registration logic here.

        """

        User = MyUser
        user = User.objects.create_user(
            username = form.cleaned_data['username'],
            first_name = form.cleaned_data['first_name'],
            last_name = form.cleaned_data['last_name'],
            email=form.cleaned_data['email'],
            password=form.cleaned_data['password1']
        )
        if not self.registration_allowed():
            return redirect(self.disallowed_url)
        return redirect(self.get_success_url(user))

from registration.forms import RegistrationForm
from django import forms
from django.forms.extras import SelectDateWidget
import datetime
from .models import MyUser

class UserProfileRegistrationForm(RegistrationForm):
    first_name = forms.CharField(max_length=15, label='First name')
    last_name = forms.CharField(max_length=15, label='Last name')
    date_of_birth = forms.DateField(label='Date of birth',
                                    widget=SelectDateWidget(years=[y for y in range(1950,
                                                                                    datetime.datetime.now().year-17)],
                                                            attrs=({'style': 'width: 20%; display: inline-block;'})),)

    class Meta:
        model = MyUser
        fields = ("email", 'first_name', 'last_name',
                  'date_of_birth')

from .views import UserProfileRegistration
urlpatterns = [

    url(r'^accounts/register/$', UserProfileRegistration.as_view(), name='registration_register'),
    url(r'^accounts/', include('registration.backends.simple.urls')),
]

'Manager' object has no attribute 'create_user'