Add a time of confirmation to the User factory

Make all users from the factory confirmed by default in an effor to save
some time and work.

spec/factories/users.rb

@@ -6,6 +6,7 @@ FactoryGirl.define do
   factory :user do
     password 'password'
     password_confirmation 'password'
+    confirmed_at Time.now - 15.minutes
     email
   end
 end