This patch allows user to use `tox -egenconfig` to directly
generate a sample conf file in etc/cloudpulse/cloudpulse.conf.sample.
This helps in vetting any doubts if the already given conf is
outdated or has incorrect config options.
Change-Id: Ib25b09c838114dd022a28b7b1b5e8d9c190a817b
wangqiangbj