Update .coveragerc after the removal of openstack directory
Update .coveragerc after the removal of openstack directory

The openstack directory was used to keep codes from oslo-incubator,
we have retired oslo-incubator,so don't use this directory any more.

Change-Id: I9ad0065bcc564dd21457ce58fc32372b22ad29cb

openstack/octavia,openstack/octavia,openstack/octavia