Updated openstack/openstack
Project: openstack/ceilometer  920cb354223b6b4a460824deb4dcc3d055a5b00e

switch to oslo-config-generator

the config generator has been moved to oslo.config. this patch
switches to use oslo.config and removes related deprecated code.

Change-Id: I9a22336142913d65da6299ea4092e170c9b2ff33