Fix metering service endpoint path spec

After installing ceilometer with the metering cookbook, invoking the
ceilometer CLI fails because the API base URL used is
http://127.0.0.1:8777/v1/v2 which means that the base endpoint path of
/v1 is incorrect and it should be simply /.

The openstack-common cookbook was updated to set the right path but we
need to update the test cases, and point to the new version of the
common cookbook.

Change-Id: I203a5a6346a3765bb249149a209122ec3d33601d
Partial-Bug: #1277742
Merge "Fix metering service endpoint path spec"