Add rake task to create CSV from check in data
user
```ruby
class Record
  attr_accessor :created_at, :meeting_date, :club_name, :leaders, :attendance,
    :notes

  def initialize(created_at, meeting_date, club_name, leaders, attendance,
                 notes)
    @created_at = created_at
    @meeting_date = meeting_date
    @club_name = club_name
    @leaders = leaders
    @attendance = attendance
    @notes = notes
  end

  # The titles of the fields that are getting put in the CSV.
  # This should be generated at runtime.
  def self.csv_title
    ['created_at', 'meeting_date', 'club_name', 'leaders', 'attendance',
     'notes']
  end

  def csv_contents
    [created_at, meeting_date, club_name, leaders, attendance, notes]
  end
end

namespace :export do 
  desc 'Generate a report of all check ins'
  task :check_ins => :environment do
    csv_string = CSV.generate do |csv|
      csv << Record.csv_title
      ::CheckIn.all.each do |check_in|
        r = Record.new(
          check_in.created_at,
          check_in.meeting_date,
          check_in.club.name,
          check_in.club.leaders.all.map { |l| l.name }.uniq,
          check_in.attendance,
          check_in.notes
        )

        csv << r.csv_contents
      end
    end

    puts csv_string
  end
end
```
assistant