Fix ansible-lint error 502 (unnamed-task) for example playbooks.

This patch adds 'name' to all example playbook tasks that did not
have it, fixing ansible-lint's error 'unnamed-task'.

playbooks/vault/ensure-symetric-vault-is-absent.yml

@@ -5,7 +5,8 @@
   gather_facts: false
 
   tasks:
-  - ipavault:
+  - name: Ensure symmetric vault is absent.
+    ipavault:
       ipaadmin_password: SomeADMINpassword
       name: symvault
       username: admin