update django REST framework version to 3.9.1
update django REST framework version to 3.9.1

Signed-off-by: Andrew Whitehead <f7337adc4e885e6dd038c60d80945a2799b03f27@gmail.com>
Signed-off-by: Wade Barnes <978ac95316789aafca50463748e5f21bf80a67d7@shaw.ca>

WadeBarnes/TheOrgBook,WadeBarnes/TheOrgBook,swcurran/TheOrgBook,WadeBarnes/TheOrgBook,swcurran/TheOrgBook,swcurran/TheOrgBook,swcurran/TheOrgBook,WadeBarnes/TheOrgBook,WadeBarnes/TheOrgBook,swcurran/TheOrgBook