Remove non-ascii characters in magnum/doc/source/dev/dev-quickstart.rst
Remove non-ascii characters in magnum/doc/source/dev/dev-quickstart.rst

"Setup Dev Environment" section has non-ascii (utf-8) characters.

Change-Id: I1f4162b22ac76ab1a1d5a2286f7d2365106bca4f
Closes-Bug: #1433496

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