Add website url for organization responsible for event stream.

[isaacchansky]

current payload looks like this:

{
  "id":1,
  "name":"Code For Boston Meetup",
  "type":"ics",
  "url":"http://www.meetup.com/Code-for-Boston/events/ical/"
}

I think it would be helpful to also have the website url for the organization behind the calendar (in this case CFB)

ex:

{
  "id":1,
  "name":"Code For Boston Meetup",
  "websiteUrl": "http://www.meetup.com/Code-for-Boston",
  "type":"ics",
  "url":"http://www.meetup.com/Code-for-Boston/events/ical/"
}