  
  matrix:
      fast_finish: true
      allow_failures:
        - TOX_ENV=py27-djangomaster
        - TOX_ENV=py34-djangomaster
        - TOX_ENV=py35-djangomaster
  
  install:
      # Virtualenv < 14 is required to keep the Python 3.2 builds running.
      - pip install tox "virtualenv<14"
  
 
</s> remove         return queryset.filter(**filter_kwargs)
 </s> add         return qs_filter(queryset, **filter_kwargs) </s> remove         if None not in checked_values and queryset.exists():
 </s> add         if None not in checked_values and qs_exists(queryset):
      - env: TOX_ENV=py27-djangomaster
      - env: TOX_ENV=py34-djangomaster
      - env: TOX_ENV=py35-djangomaster
  
  matrix:
      fast_finish: true
      allow_failures:
      - env: TOX_ENV=py27-djangomaster
      - env: TOX_ENV=py34-djangomaster
      - env: TOX_ENV=py35-djangomaster
      - env: TOX_ENV=py27-djangomaster
      - env: TOX_ENV=py34-djangomaster
      - env: TOX_ENV=py35-djangomaster
      - env: TOX_ENV=py27-djangomaster
      - env: TOX_ENV=py34-djangomaster
      - env: TOX_ENV=py35-djangomaster
  
  install:
      # Virtualenv < 14 is required to keep the Python 3.2 builds running.
      - pip install tox "virtualenv<14"
  
keep keep keep keep replace replace replace keep keep keep keep keep
 Robust uniqueness checks. (#4217)

* Robust uniqueness checks
* Add master to test matrix (allow_failures) 
.travis.yml