Change nova ram_allocation_ratio to match puppet-nova
Change nova ram_allocation_ratio to match puppet-nova

The interface for this moved to init.pp, the one we currently
use now only outputs a warning, it doesn't actually set anything.

Change-Id: Idc40cf0dc4ff0f598e0918e0de8b3233b524cdd5
Closes-Bug: 1638254

openstack/tripleo-heat-templates,dprince/tripleo-heat-templates,dprince/tripleo-heat-templates,openstack/tripleo-heat-templates