Add simple plugin that times ansible-playbook runs.

plugins/callbacks/timer.py

+import os
+import datetime
+from datetime import datetime, timedelta
+
+
+class CallbackModule(object):
+    """
+    This callback module tells you how long your plays ran for.
+    """
+
+    start_time = datetime.now()
+    
+    def __init__(self):
+        start_time = datetime.now()
+        print "Timer plugin is active."
+
+    def days_hours_minutes_seconds(self, timedelta):
+        minutes = (timedelta.seconds//60)%60
+        r_seconds = timedelta.seconds - (minutes * 60)
+        return timedelta.days, timedelta.seconds//3600, minutes, r_seconds
+
+    def playbook_on_stats(self, stats):
+        end_time = datetime.now()
+        timedelta = end_time - self.start_time
+        print "Playbook run took %s days, %s hours, %s minutes, %s seconds" % (self.days_hours_minutes_seconds(timedelta))
+
+