baro: updating refs to collectd-ceilometer

baro: updating refs to collectd-ceilometer

Since Ceilometer support was removed from the
collectd-ceilometer-plugin[1], the repo name and ceiloemter are
misleading. A change was submitted to openstack-infra to rename
the repo [2]

This change removes references to collectd-ceilometer from apex.
These changes are independant of the repo rename.

[1] https://review.openstack.org/#/c/490823/
[2] https://review.openstack.org/#/c/500768/

Depends-On: I6cf22c081aa1e40f64995be40b6225855faf4092
Change-Id: Ib3a7766e28fd03a86a995eea4b9abc996498200e
Signed-off-by: Emma Foley <emma.l.foley@intel.com>