try: downgrade djangorestframework

Author: Naramsim

requirements.txt

@@ -7,7 +7,7 @@ django-discover-runner==1.0
 django-redis==4.10.0
 django-cachalot==2.3.5
 django-tastypie==0.14.3
-djangorestframework==3.10.3
+djangorestframework==3.9.0
 drf-ujson==1.2.0
 gunicorn==20.1.0
 mimeparse==0.1.3