Add python3-compat boilerplate to all .py files in lib/ansible

lib/ansible/plugins/callback/timer.py

@@ -1,3 +1,7 @@
+# Make coding more python3-ish
+from __future__ import (absolute_import, division, print_function)
+__metaclass__ = type
+
 import os
 import datetime
 from datetime import datetime, timedelta