drf-extensions 0.5 drops python 2 support and causes other breakages, so pin ourselves to the old version until we can drop python 2
drf-extensions 0.5 drops python 2 support and causes other breakages, so pin ourselves to the old version until we can drop python 2

CTPUG/wafer,CTPUG/wafer,CTPUG/wafer,CTPUG/wafer