title: Update field of onetoone related model with django form
body: <p>In models.py:</p>
  
  <pre><code>class UserProfile(models.Model):
      user = AutoOneToOneField(User, on_delete=models.CASCADE)
      avatar = models.ImageField(upload_to='user_avatars/', default = 'user_avatars/default-avatar.jpg')
      male = 'M'
      female = 'F'
      gender_choices = ((male,'Male'), (female,'Female'))
      gender = models.CharField(choices = gender_choices, max_length = 10)
      dateOfBirth = models.DateField(default = datetime.date.today)
      follows = models.ManyToManyField("self", related_name = 'followers', symmetrical=False,\
                                          blank = True)
      favorite_pet = models.ManyToManyField(Pet, blank = True)
  
      def __str__(self):
          return self.user.username
  </code></pre>
  
  <p>In forms.py:</p>
  
  <pre><code>class EditProfileForm(forms.ModelForm):
  
      first_name = forms.CharField(label='First Name')
      last_name = forms.CharField(label='Last Name')
      email = forms.EmailField()
      gender_choices = (('M', 'Male'), ('F', 'Female'))
      gender = models.CharField(choices=gender_choices, max_length=10)
      dateOfBirth = models.DateField()
  
      class Meta:
          model = User
          fields = ['first_name', 'last_name', 'email']
  </code></pre>
  
  <p>I want to allow users to change their <code>gender</code> and <code>dateOfBirth</code>. However, these fields belong to <code>UserProfile</code> class (which has one-to-one relationship with <code>User</code>), thus if I add 'gender' and 'dateOfBirth' to array fields in meta class I will get "unknown fields" error from <code>User</code> class. Could anyone show me how to achieve  my goal? Any help will be highly appreciated :D</p>