Fix nova client initialization arguments
Fix nova client initialization arguments

We already have token and endpoints in context, so, just pass them to
the nova client.

Change-Id: Ic35e275fd404e83e02b503fa8ee8c1c372885e8b

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