Add to bootstrap image packages for distributed serialization

There are packges python-dispy and python-psutil that requares for
the distributed serialization.

Change-Id: Ife24b7de4eb1146cbe2a5a0c936f61a586d97e95
Implements: blueprint distributed-serialization

contrib/fuel_bootstrap/files/xenial/usr/bin/fix-configs-on-startup

@@ -70,3 +70,6 @@ while true; do
 done
 echo "identity = $(head -n 1 /etc/nailgun_uid)" >> /etc/mcollective/server.cfg
 service mcollective restart
+
+# restart the dispynode service
+systemctl restart dispynode

contrib/fuel_bootstrap/fuel_bootstrap_cli/fuel_bootstrap/settings.yaml.sample

@@ -54,6 +54,9 @@ packages:
   - ifenslave
   - irqbalance
   - iputils-arping
+  # Packages required for distributed serialization
+  - python-dispy
+  - python-psutil
 # Ignore proxy for this repos
 #direct_repo_addresses:
 #    - 127.0.0.1