Use faker gem for Member factorybot

spec/factories/member.rb

@@ -3,9 +3,9 @@ FactoryBot.define do
   sequence(:login_name) { |n| "member#{n}" }
 
   factory :member, aliases: %i(author owner sender recipient creator) do
-    login_name { generate(:login_name) }
+    login_name { Faker::Name.unique.first_name }
     password 'password1'
-    email { generate(:email) }
+    email { Faker::Internet.unique.email }
     tos_agreement true
     confirmed_at Time.now
     show_email false