Refactoring Tickets

- Tickets now independent from registration
- Implemented money gem
#419

app/controllers/ticket_purchases_controller.rb

@@ -0,0 +1,29 @@
+class TicketPurchasesController < ApplicationController
+  before_filter :verify_user
+  load_resource :conference, find_by: :short_title
+  authorize_resource :conference_registrations, class: Registration
+
+  def create
+    message = TicketPurchase.purchase(@conference, current_user, params[:tickets][0])
+    if message.blank?
+      redirect_to conference_conference_registrations_path(@conference.short_title),
+                  notice: "Congratulations, you have successfully purchased a ticket! " \
+                    "You can pay it cash on check in! Thank you for supporting #{@conference.title}!"
+    else
+      redirect_to conference_conference_registrations_path(@conference.short_title),
+                  alert: "Oops, something went wrong with your purchase! #{message}"
+    end
+  end
+
+  def destroy
+    @ticket_purchases = current_user.ticket_purchases.find_by(ticket_id: params[:id])
+    if @ticket_purchases.destroy
+      redirect_to conference_conference_registrations_path(@conference.short_title),
+                  notice: 'Ticket successfully destroyed.'
+    else
+      redirect_to conference_conference_registrations_path(@conference.short_title),
+                  notice: "A error prohibited deleting your purchase! "\
+                        "#{@ticket_purchases.errors.full_messages.join('. ')}."
+    end
+  end
+end