added codecov to travis.yml
added codecov to travis.yml

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