Update developer quickstart
Update developer quickstart

Change-Id: I831ff93d1f5d180a88cdbb8b23ab330af561f7d8
Closes-Bug: #1410454

openstack/magnum,LaynePeng/magnum,eshijia/magnum,ddepaoli3/magnum,paulczar/magnum,paulczar/magnum,annegentle/magnum,mjbrewer/testindex,Alzon/SUR,LaynePeng/magnum,sajuptpm/magnum,ramielrowe/magnum,ChengTiesheng/magnum,mjbrewer/testindex,ArchiFleKs/magnum,openstack/magnum,eshijia/SUR,mjbrewer/testindex,dimtruck/magnum,hongbin/magnum,ddepaoli3/magnum,jay-lau/magnum,sajuptpm/magnum,ChengTiesheng/magnum,ffantast/magnum,ramielrowe/magnum,Tennyson53/magnum,Tennyson53/magnum,Tennyson53/SUR,Alzon/SUR,eshijia/magnum,dimtruck/magnum,eshijia/SUR,Tennyson53/SUR,annegentle/magnum,ffantast/magnum,ArchiFleKs/magnum,hongbin/magnum