[libvirt] expose node hostname

lib/fog/libvirt/models/compute/node.rb

@@ -24,6 +24,7 @@ module Fog
         attribute :manufacturer
         attribute :product
         attribute :serial
+        attribute :hostname
 
       end
 

lib/fog/libvirt/requests/compute/get_node_info.rb

@@ -17,6 +17,7 @@ module Fog
             node_hash[attr] = node_attr(attr, xml)
           end
 
+          node_hash[:hostname] = client.hostname
           [node_hash]
         end