title: Choices function in Django Models giving Error: Select a valid choice. 2 is not one of the available choices
body: <p>Unable to set rating choice through Django admin console
  Error: Select a valid choice. 2 is not one of the available choices.</p>
  
  <p>models.py</p>
  
  <pre><code>    from model_utils import Choices
  
  class Course_Feedback(models.Model):
      course = models.ForeignKey(Course, on_delete=models.PROTECT, related_name='course_feedback')
      RATING = Choices(1, 2, 3, 4, 5)
      rating = models.CharField(choices=RATING, null=True, max_length=2)
  </code></pre>
  
  <p>cant we use integers in choices directly ?</p>