Issue/49 add restart streaks to schedule

lib/tasks/email_sender.rake

 namespace :email_users do 
 
     task :email_sender => :environment do
-        user = User.where("email = 'admin@inf.ufpr.br'").first_or_create
+        user = User.where("email = 'admin@inf.ufpr.br'").first
         UserMailer.users_email_sender(user).deliver_now!
     end