added new python and django versions and drop pypy from matrix
added new python and django versions and drop pypy from matrix

justquick/django-activity-stream,jrsupplee/django-activity-stream,pombredanne/django-activity-stream,justquick/django-activity-stream,pombredanne/django-activity-stream,thelabnyc/django-activity-stream,jrsupplee/django-activity-stream,thelabnyc/django-activity-stream