Use the charmhelpers.core.templating template rendering logic
instead of the charmhelpers.core.services template rendering logic
when generating the hdparm.conf file.
Change-Id: I4b9718e49336d72501585279c0fc0cfcd465abb2
Closes-Bug: #1660240
Helper functions for the ceph charms. This library has shared functionality that is used in the ceph-mon, ceph-osd and ceph
charms. Anything that needs to be shared across the ceph charms should live here.