$ python manage.py makemigrations

Migrations for 'core':
  core/migrations/0001_initial.py
    - Create model User

class Migration(migrations.Migration):

    initial = True

    dependencies = [
        ('auth', '0009_alter_user_last_name_max_length'),
    ]

$ python manage.py migrate
Operations to perform:
  Apply all migrations: admin, auth, contenttypes, core, sessions
Running migrations:
  Applying contenttypes.0001_initial... OK
  Applying contenttypes.0002_remove_content_type_name... OK
  Applying auth.0001_initial... OK
  Applying auth.0002_alter_permission_name_max_length... OK
  Applying auth.0003_alter_user_email_max_length... OK
  Applying auth.0004_alter_user_username_opts... OK
  Applying auth.0005_alter_user_last_login_null... OK
  Applying auth.0006_require_contenttypes_0002... OK
  Applying auth.0007_alter_validators_add_error_messages... OK
  Applying auth.0008_alter_user_username_max_length... OK
  Applying auth.0009_alter_user_last_name_max_length... OK
  Applying core.0001_initial... OK
  Applying admin.0001_initial... OK
  Applying admin.0002_logentry_remove_auto_add... OK
  Applying sessions.0001_initial... OK

class Migration(migrations.Migration):

    initial = True

    dependencies = [
        migrations.swappable_dependency(settings.AUTH_USER_MODEL),
    ]

class UserManager(BaseUserManager):
    def create_user(self, email, password=None):
        if not email:
            raise ValueError('Email not defined.')

        user = self.model(email=self.normalize_email(email))

        user.set_password(password)
        user.save(using=self._db)
        return user

    def create_superuser(self, email, password):
        user = self.create_user(
            email,
            password=password,
        )
        user.is_staff = True
        user.save(using=self._db)
        return user


class User(AbstractBaseUser, PermissionsMixin):
    email = models.EmailField(unique=True)
    created_at = models.DateTimeField(auto_now_add=True)
    is_staff = models.BooleanField(default=False)
    is_active = models.BooleanField(default=True)

    EMAIL_FIELD = 'email'
    USERNAME_FIELD = 'email'

    objects = UserManager()

    def __str__(self):
        return self.email

    def has_perm(self, perm, obj=None):
        return True

    def has_module_perms(self, app_label):
        return True