base: Add munin-node and update policy

munin-node adds depency to external repos so also update package
policy.

roles/base/README.md

@@ -1,12 +1,22 @@
 ## Ansible Role: base
 
-This role is applied to all hosts. This role must not have any package
-depencies outside operating system's base packages.
+This role is applied to all hosts.
 
 ### Basic service
 
 This role will install and configure following base services using
 operating system default software:
+
  * mail sending to local (foo.sh) addresses using smtps port
  * system logging to remote host
  * ssh server (tighten crypto settings)
+
+These services must not have any depencies outside of operating
+system's base packages.
+
+### Secondary services
+
+Following secondary services that are not required for production
+capability are installed:
+
+ * munin-node for monitoring system usage

roles/base/tasks/main.yml

@@ -29,6 +29,7 @@
   include_role:
     name: "{{ role }}"
   with_items:
+    - munin-node
     - network
     - pki
     - psacct