README.rst: make it us-ascii
README.rst: make it us-ascii

Change-Id: I3248ca3d1639b35bb531d629b390d681f34bacd6

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