[Organizer] Confirming RSVP-ed YES member as attendee

[zgperak]

As an organizer

• [ ] Scenario: Organizers can confirm attendance of RSVP-ed YES members

  Given there is a 'Some event' event of an organization 'Local meetup'
  And 'Some event' has started
  And 'Alex Smith' is an organizer of 'Local meetup' organization
  And 'Jo Johnson' RSVP YES to an 'Some event' event
  When 'Alex Smith' confirm 'Jo Johnson' attendance to an 'Some event'
  Than  'Jo Johnson' is confirmed attendee of an 'Some event'