Use SSD disk for journal device

Try to find out if device is SSD disk, and use it for journal device


https://github.com/crowbar/barclamp-deployer/pull/211 is required
this simply selects one device as ssd per node. it would be nicer to use all available SSDs equally for all OSDs per node. 

e.g. every #{number_of_osds}/#{number_of_ssds} use a new ssd.