Updated README example to show that attendees come with past events

Author: estebistec

README.rst

@@ -29,7 +29,7 @@ Example Usage
     u'Monthly Meetup: Google App Engine'
     >>> last_meetup.time
     datetime.datetime(2011, 7, 9, 14, 0, tzinfo=tzoffset(None, -18000))
-    >>> an_attendee = meetups.get_event_attendees(last_meetup.id)[0]
+    >>> an_attendee = last_meetup.attendees[0]
     >>> an_attendee.name
     u'Steven Cummings'
     >>> an_attendee.photo.thumb_url