Registration tickets to be set for registration period

Admin must create at least one registration ticket before creating registration period.

spec/models/admin_ability_spec.rb

@@ -11,6 +11,7 @@ describe 'User with admin role' do
 
     let!(:organization) { create(:organization) }
     let!(:my_conference) { create(:full_conference, organization: organization) }
+    let!(:registration_ticket) { create(:registration_ticket, conference: my_conference) }
     let(:my_venue) { my_conference.venue || create(:venue, conference: my_conference) }
     let(:my_registration) { create(:registration, conference: my_conference, user: admin) }
 

spec/models/registration_period_spec.rb

@@ -2,6 +2,7 @@ require 'spec_helper'
 
 describe RegistrationPeriod do
   let!(:conference) { create(:conference, start_date: Date.today, end_date: Date.today + 6) }
+  let!(:registration_ticket) { create(:registration_ticket, conference: conference) }
   let!(:registration_period) { create(:registration_period, start_date: Date.today - 2, end_date: Date.today - 1, conference: conference) }
 
   describe 'validations' do