text: Title: latest dbfixtures release breaks unit tests
  Body: See this commit:
  
  https://github.com/ClearcodeHQ/pytest-dbfixtures/commit/572629afc475f446fda09fabc4d33a613dd2af6f
  
  Note that passing '?' into the fixtures (see https://github.com/manahl/arctic/blob/master/arctic/fixtures/arctic.py#L15 ) looks to be no longer supported. 
  