Allow creating of crush location buckets

[Dan Williams]

When creating a deployment a mechanism to create crush location buckets of various types would be very useful. At present the default location of root=<default> host=<hostname> is used.

If osd_crush_update_on_start is set to true and the location is set as a global attribute the OSDs do not end up in the correct location within the crush map.

Maybe we could have something like:

ceph::crush::bucket {
  name => <string>,
  type => <int>,
  parent => <string>, defining the name of the parent bucket
}