text: Title: Please release new version - Cannot revoke all tokens: AccessToken matching query does not exist
  Body: I am getting a DoesNotExist exception trying to clean up when a user logs out.
  
  
  django-oauth-toolkit==1.2.0
  
  ```
  from itertools import chain
  from oauth2_provider.models import get_access_token_model, get_application_model, get_refresh_token_model
  
      access_tokens = get_access_token_model().objects.filter(user=user)
      refresh_tokens = get_refresh_token_model().objects.filter(user=user)
  
      for token in chain(access_tokens, refresh_tokens):
          token.revoke()
  
  ```
  
  
  It appears this is fixed in master: https://github.com/jazzband/django-oauth-toolkit/blob/master/oauth2_provider/models.py#L397
  
  It looks like the fix is a year old: https://github.com/jazzband/django-oauth-toolkit/commit/5b51da74019046ef4c8c81c9975db029a2113d52#diff-ac3d3b1e30eb6e828386263c3a1256ca
  
  Please release a new version.