Remove out of date TODOs from README
Remove out of date TODOs from README

Change-Id: Ife6baf7ae7697d9a60d0d1b8d26344c39b951616

ramsateesh/designate,ramsateesh/designate,kiall/designate-py3,openstack/designate,cneill/designate,cneill/designate-testing,muraliselva10/designate,kiall/designate-py3,ionrock/designate,kiall/designate-py3,richm/designate,grahamhayes/designate,richm/designate,cneill/designate,cneill/designate-testing,NeCTAR-RC/designate,openstack/designate,grahamhayes/designate,NeCTAR-RC/designate,cneill/designate-testing,tonyli71/designate,kiall/designate-py3,grahamhayes/designate,cneill/designate,melodous/designate,melodous/designate,ionrock/designate,cneill/designate,melodous/designate,kiall/designate-py3,melodous/designate,cneill/designate,tonyli71/designate,openstack/designate,ionrock/designate,ramsateesh/designate,muraliselva10/designate,tonyli71/designate,muraliselva10/designate