Update with_items loops to use new-ish "loop" keyword

Ansible 2.4 and 2.5 are moving away from specialized loop functions
and the old syntax will eventually be deprecated and removed. I did
not change the with_fileglob loops because I'm not sure about their
syntax yet.

See: https://docs.ansible.com/ansible/latest/user_guide/playbooks_loops.html

roles/common/tasks/cron-apt.yml

@@ -2,7 +2,7 @@
 
 - name: Configure cron-apt (config)
   copy: src={{ item.src }} dest={{ item.dest }} mode={{ item.mode }} owner={{ item.owner }} group={{ item.group }}
-  with_items:
+  loop:
     - { src: 'etc/cron-apt/config', dest: '/etc/cron-apt/config', mode: '0644', owner: 'root', group: 'root' }
     - { src: 'etc/cron-apt/3-download', dest: '/etc/cron-apt/action.d/3-download', mode: '0644', owner: 'root', group: 'root' }