Working deploy for controller and compute nodes

- use 'dash' branch for mk-lab-salt-model repo (it has a lot of
  improvements and fixes)
- use less number of nodes to match the 'mk22-lab-advanced' model
- force update packages before configuring salt.minions
- use saltstack repo for latest salt.minions on trusty

* Note if the deploy starts from an 'underlay' snapshot,
  keepalived can lose VIP after update DHCP leases on nodes.
  It's better to start deploy from clean environment.
diff --git a/tcp_tests/settings_oslo.py b/tcp_tests/settings_oslo.py
index 7e8490d..6ba5b3c 100644
--- a/tcp_tests/settings_oslo.py
+++ b/tcp_tests/settings_oslo.py
@@ -42,6 +42,7 @@
     ct.Cfg('ssh', ct.JSONList(),
            help="""SSH Settings for Underlay: [{
                   'node_name': node1,
+                  'roles': ['salt-master', 'salt-minion', ],
                   'host': hostname,
                   'login': login,
                   'password': password,