add stripe-gem and payment schema

db/migrate/20160606040848_create_payments.rb

@@ -0,0 +1,14 @@
+class CreatePayments < ActiveRecord::Migration
+  def change
+    create_table :payments do |t|
+      t.string :last4, null: false
+      t.integer :amount, null: false
+      t.string :authorization_code, null: false
+      t.integer :status, default: 0, null: false
+      t.integer :user_id, null: false
+      t.integer :conference_id, null: false
+
+      t.timestamps null: false
+    end
+  end
+end

db/migrate/20160610073948_add_payment_id_to_ticket_purchases.rb

@@ -0,0 +1,5 @@
+class AddPaymentIdToTicketPurchases < ActiveRecord::Migration
+  def change
+    add_column :ticket_purchases, :payment_id, :integer
+  end
+end