title: Django error while creating superuser, AttributeError: 'Manager' object has no attribute 'get_by_natural_key'
body: <p>I am using Django version 1.11.3 and djangorestframework version 3.6.3. At the stage of creating the superuser with the following command: </p>
  
  <pre><code>python manage.py createsuperuser
  </code></pre>
  
  <p>This command was supposed to ask me about my Email and Password, though it does ask me the Email but after entering my Email, I got an error: </p>
  
  <pre><code>Traceback (most recent call last):
    File "manage.py", line 22, in &lt;module&gt;
      execute_from_command_line(sys.argv)
    File "/home/shivams334/myapp2/lib/python3.5/site-packages/django/core/management/__init__.py", line 363, in execute_from_command_line
      utility.execute()
    File "/home/shivams334/myapp2/lib/python3.5/site-packages/django/core/management/__init__.py", line 355, in execute
      self.fetch_command(subcommand).run_from_argv(self.argv)
    File "/home/shivams334/myapp2/lib/python3.5/site-packages/django/core/management/base.py", line 283, in run_from_argv
      self.execute(*args, **cmd_options)
    File "/home/shivams334/myapp2/lib/python3.5/site-packages/django/contrib/auth/management/commands/createsuperuser.py", line 63, in execute
      return super(Command, self).execute(*args, **options)
    File "/home/shivams334/myapp2/lib/python3.5/site-packages/django/core/management/base.py", line 330, in execute
      output = self.handle(*args, **options)
    File "/home/shivams334/myapp2/lib/python3.5/site-packages/django/contrib/auth/management/commands/createsuperuser.py", line 121, in handle
      self.UserModel._default_manager.db_manager(database).get_by_natural_key(username)
  AttributeError: 'Manager' object has no attribute 'get_by_natural_key'
  </code></pre>
  
  <p>My models.py is this:</p>
  
  <pre><code>from django.db import models
  from django.contrib.auth.models import AbstractBaseUser
  from django.contrib.auth.models import PermissionsMixin
  from django.contrib.auth.models import BaseUserManager
  
  class UserProfileManager(object):
      """helps django work with our custom user model"""
      def create_user(self,email,name,password=None):
          if not email:
              raise ValueError('User must have email')
          email = self.normalize_email(email)
          user = self.model(email=email, name=name)
  
          user.set_password(password)
          user.save(using=self._db)
  
          return user
      def create_superuser(self,email,name,password):
          """creates and saves a new superuser with given details"""
          user = self.create_user(email,name,password)
          user.is_superuser = True
          user.is_staff = True
          user.save(using=self._db)   
  
  class UserProfile(AbstractBaseUser, PermissionsMixin):
  
      """docstring for UserProfile"""
      email = models.EmailField(max_length=255, unique=True)
      name = models.CharField(max_length=255)
      is_active = models.BooleanField(default=True)
      is_staff = models.BooleanField(default=False)
  
      objects = UserProfileManager()
  
      USERNAME_FIELD = 'email'
      REQUIRED_FIELDS = ['name']
  
      def get_full_name(self):
          """used to get a user full name"""
          return self.name
  
      def get_short_name():
          """used to get a users short name"""
          return self.name
  
      def __str__(self):
          """Django uses this when it needs to convert the object into string"""
          return self.email
  </code></pre>
  
  <p>And I also updated the Application Definition in settings.py:</p>
  
  <pre><code>INSTALLED_APPS = [
      'django.contrib.admin',
      'django.contrib.auth',
      'django.contrib.contenttypes',
      'django.contrib.sessions',
      'django.contrib.messages',
      'django.contrib.staticfiles',
      'rest_framework',
      'rest_framework.authtoken',
      'profiles_api',
  ]
  AUTH_USER_MODEL = 'profiles_api.UserProfile'
  </code></pre>
  
  <p>I have tried to do this with both python2 and python3 but the error is same.</p>