aded tests for str methods
aded tests for str methods

modle/django-star-ratings,webu/django-star-ratings,modle/django-star-ratings,webu/django-star-ratings,modle/django-star-ratings,modle/django-star-ratings,modle/django-star-ratings,webu/django-star-ratings,webu/django-star-ratings,webu/django-star-ratings