Fix python-etcd client installation process
Fix python-etcd client installation process

python-etcd was not installed correctly on new machines
this patch fixes this installation process

Change-Id: If2e5a8ed542ee951bfb04291387c6af560bfcd86

FrankDuan/df_code,neoareslinux/dragonflow,openstack/dragonflow,openstack/dragonflow,neoareslinux/dragonflow,openstack/dragonflow,FrankDuan/df_code,FrankDuan/df_code