tests(admin): add some docstrings to TestCase classes
tests(admin): add some docstrings to TestCase classes

dsanders11/django-advanced-filters,modlinltd/django-advanced-filters,PreppyLLC-opensource/django-advanced-filters,dsanders11/django-advanced-filters,dsanders11/django-advanced-filters,PreppyLLC-opensource/django-advanced-filters,dsanders11/django-advanced-filters,modlinltd/django-advanced-filters,modlinltd/django-advanced-filters,PreppyLLC-opensource/django-advanced-filters