Add ability to specify custom node name in reclass.

In terms of PR to salt formula:
https://github.com/salt-formulas/salt-formula-salt/pull/44
I would like to introduce this changes in model.
diff --git a/salt/control/cluster/stacklight_server_cluster.yml b/salt/control/cluster/stacklight_server_cluster.yml
index 560892a..0055d20 100644
--- a/salt/control/cluster/stacklight_server_cluster.yml
+++ b/salt/control/cluster/stacklight_server_cluster.yml
@@ -13,14 +13,17 @@
           engine: virt
           node:
             mon01:
+              name: ${_param:stacklight_monitor_node01_hostname}
               provider: ${_param:infra_kvm_node01_hostname}.${_param:cluster_domain}
               image: ${_param:salt_control_xenial_image}
               size: stacklight.server
             mon02:
+              name: ${_param:stacklight_monitor_node02_hostname}
               provider: ${_param:infra_kvm_node02_hostname}.${_param:cluster_domain}
               image: ${_param:salt_control_xenial_image}
               size: stacklight.server
             mon03:
+              name: ${_param:stacklight_monitor_node03_hostname}
               provider: ${_param:infra_kvm_node03_hostname}.${_param:cluster_domain}
               image: ${_param:salt_control_xenial_image}
               size: stacklight.server