Added model test

Added test for physical ticket model.

spec/models/physical_ticket_spec.rb

@@ -0,0 +1,14 @@
+require 'spec_helper'
+
+describe PhysicalTicket do
+
+  describe 'association' do
+    it { is_expected.to belong_to :ticket_purchase }
+  end
+
+  describe 'validations' do
+    it 'has a valid factory' do
+      expect(build(:physical_ticket)).to be_valid
+    end
+  end
+end