Handle zero as valid pk/id in get_resource_id util method#1245

sliverc merged 4 commits intodjango-json-api:maindjango-json-api/django-rest-framework-json-api:mainfrom

humayunah:handle-zero-id-in-get_resource_idhumayunah/django-rest-framework-json-api:handle-zero-id-in-get_resource_idCopy head branch name to clipboard