Fix test to work on Python 2.6
Fix test to work on Python 2.6

vstoykov/django-hvad,ojii/django-nani,promil23/django-hvad,vstoykov/django-hvad,ojii/django-nani,promil23/django-hvad,philippeowagner/django-hvad,philippeowagner/django-hvad,piha/django-hvad,hds/django-hvad,hds/django-hvad,piha/django-hvad