Add specs for model facebook_page (#346)

spec/factories/channel/facebook_pages.rb

@@ -0,0 +1,11 @@
+# frozen_string_literal: true
+
+FactoryBot.define do
+  factory :channel_facebook_page, class: Channel::FacebookPage do
+    name { Faker::Name.name }
+    page_access_token { SecureRandom.uuid }
+    user_access_token { SecureRandom.uuid }
+    page_id { SecureRandom.uuid }
+    account
+  end
+end