Run cephadm_pool task as sudo

The `cephadm_pool` Ansible module
now explicitly uses `become: true` to ensure
it is executed with elevated privileges.

This change is necessary because `cephadm`
requires sudo permissions to manage Ceph pools.

Resolves #169

Author: keuko

roles/pools/tasks/main.yml

@@ -17,3 +17,4 @@
   with_items: "{{ cephadm_pools }}"
   delegate_to: "{{ groups['mons'][0] }}"
   run_once: true
+  become: true