Fix : django-filter looks for 'filterset_class' attribute now #98

Job	Run time
Python==3.6 \| py36-django22-djangorestframework310	1m 56s
Python==3.7 \| py37-django22-djangorestframework310	2m 11s
Python==3.8 \| py38-django22-djangorestframework310	1m 54s
Python==3.9 \| py39-django22-djangorestframework310	1m 56s
Python==3.6 \| py36-django22-djangorestframework312	2m 21s
Python==3.7 \| py37-django22-djangorestframework312	1m 54s
Python==3.8 \| py38-django22-djangorestframework312	2m 1s
Python==3.9 \| py39-django22-djangorestframework312	1m 49s
Python==3.6 \| py36-django30-djangorestframework312	2m 28s
Python==3.7 \| py37-django30-djangorestframework312	2m 16s
Python==3.8 \| py38-django30-djangorestframework312	2m 8s
Python==3.9 \| py39-django30-djangorestframework312	1m 47s
Python==3.6 \| py36-django31-djangorestframework312	2m 24s
Python==3.7 \| py37-django31-djangorestframework312	1m 54s
Python==3.8 \| py38-django31-djangorestframework312	1m 48s
Python==3.9 \| py39-django31-djangorestframework312	1m 49s
Python==3.7 \| py37-django32-djangorestframework312	1m 46s
Python==3.8 \| py38-django32-djangorestframework312	1m 51s
Python==3.9 \| py39-django32-djangorestframework312	1m 46s
Python==3.8 \| py38-django40-djangorestframework313	2m 12s
Python==3.9 \| py39-django40-djangorestframework313	2m 21s
Finish Coveralls	0s
	42m 32s

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