Send mail on ticket confirmation.

Added mailer method to send ticket confirmation email along with the attached pdf for ticket.

app/models/ticket_purchase.rb

@@ -69,6 +69,7 @@ class TicketPurchase < ActiveRecord::Base
     PhysicalTicket.transaction do
       quantity.times { physical_tickets.create }
     end
+    Mailbot.ticket_confirmation_mail(self).deliver_later
   end
 end