Local events feed (Happenings)

Resubmitting after review
This is a weird case of the pattern that I harp on about with `.inject`. The method you want here is `.tap`:

```
Icalendar::Event.new.tap do |ical_event|
  ical_event.uid         = "#{id}"
  ical_event.dtstart     = time
  ical_event.summary     = name
  ical_event.location    = location
  ical_event.description = "#{name} at #{location}"
  ical_event.url         = link
  ical_event.ip_class    = "PRIVATE"
end