Add runtests.py as recommended by django
Add runtests.py as recommended by django

https://docs.djangoproject.com/en/1.8/topics/testing/advanced/#using-the-django-test-runner-to-test-reusable-applications

michalwerner/django-filebrowser,michalwerner/django-filebrowser,michalwerner/django-filebrowser,michalwerner/django-filebrowser-tinymce4,djkartsa/django-filebrowser-no-grappelli,michalwerner/django-filebrowser-tinymce4,michalwerner/django-filebrowser-tinymce4,djkartsa/django-filebrowser-no-grappelli,djkartsa/django-filebrowser-no-grappelli