Install etckeeper and run hourly

This automatically logs all changes made to /etc in git and is
useful for debugging purposes, while it doesn't hurt.

Author: eldering

provision-contest/ansible/roles/base_packages/defaults/main.yml

@@ -16,6 +16,7 @@ INSTALLED_PACKAGES:
   - debootstrap
   - default-jdk-headless
   - efibootmgr
+  - etckeeper
   - fontconfig
   - g++
   - gcc

provision-contest/ansible/roles/system_fixes/tasks/main.yml

@@ -65,5 +65,13 @@
         line: 'DNS=8.8.8.8'
       notify: Reboot the machine
 
+- name: stat /etc/cron.daily/etckeeper
+  stat: path=/etc/cron.daily/etckeeper
+  register: daily_etckeeper
+
+- name: Enable etckeeper autocommits every hour
+  command: mv /etc/cron.daily/etckeeper /etc/cron.hourly/etckeeper
+  when: daily_etckeeper.stat.exists
+
 - name: Flush handlers
   meta: flush_handlers