add some rspec tests for supplier and article

spec/factories/supplier.rb

@@ -0,0 +1,19 @@
+require 'factory_girl'
+
+FactoryGirl.define do
+
+  factory :supplier do
+    name { Faker::Company.name }
+    phone { Faker::PhoneNumber.phone_number }
+    address { Faker::Address.street_address }
+
+    ignore do
+      article_count 0
+    end
+
+    after :create do |supplier, evaluator|
+      FactoryGirl.create_list :article, evaluator.article_count, supplier: supplier
+    end
+  end
+
+end