Fixed wrong use of testtools.ExpectedException
Fixed wrong use of testtools.ExpectedException

Change-Id: Ifc4b2a7c52346fd5fb6d9d023236a13afd0f30ec

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