Fix a auth_uri cannot get in sahara-engine
Fix a auth_uri cannot get in sahara-engine

Fixed a clone method in sahara.Context that didn't cloned a auth_uri.

Change-Id: Ic8a26791e58ef1dc184f0038b0405e0c0e2df430

redhat-openstack/sahara,xme1226/sahara,egafford/sahara,zhangjunli177/sahara,esikachev/sahara-backup,esikachev/scenario,matips/iosr-2015,keedio/sahara,keedio/sahara,mapr/sahara,citrix-openstack-build/sahara,zhangjunli177/sahara,bigfootproject/sahara,ekasitk/sahara,openstack/sahara,crobby/sahara,matips/iosr-2015,henaras/sahara,xme1226/sahara,esikachev/scenario,henaras/sahara,bigfootproject/sahara,zhujzhuo/Sahara,crobby/sahara,henaras/sahara,mapr/sahara,redhat-openstack/sahara,egafford/sahara,zhujzhuo/Sahara,bigfootproject/sahara,esikachev/sahara-backup,ekasitk/sahara,zhujzhuo/Sahara,mapr/sahara,zhangjunli177/sahara,tellesnobrega/sahara,citrix-openstack-build/sahara,esikachev/sahara-backup,tellesnobrega/sahara,ekasitk/sahara,crobby/sahara,citrix-openstack-build/sahara,keedio/sahara,openstack/sahara,xme1226/sahara,esikachev/scenario,redhat-openstack/sahara,matips/iosr-2015