Make ticket layout configurable

Added option for conference organizer to switch between ticket layouts (horizontal or vertical). Added test for the same.

app/controllers/physical_ticket_controller.rb

@@ -12,5 +12,6 @@ class PhysicalTicketController < ApplicationController
   def show
     @file_name = "ticket_for_#{@conference.short_title}"
     @user = @physical_ticket.user
+    @ticket_layout = @conference.ticket_layout.to_sym
   end
 end