Add Tempest Run option to README
Add Tempest Run option to README

This patch adds "tempest run" as one of the options to run
the monasca tempest tests.

See bp tempest-run-cmd for details.

Change-Id: Idcfa09b86775642e5f3698d2a2ec8ffd7e39b817

sapcc/monasca-api,stackforge/monasca-api,stackforge/monasca-api,openstack/monasca-api,stackforge/monasca-api,openstack/monasca-api,sapcc/monasca-api,openstack/monasca-api,stackforge/monasca-api,sapcc/monasca-api