title: Sidekiq jobs running endlessly
body: <p>I am using <code>rails 5</code> and <code>sidekiq (4.1.2)</code> on <code>Heroku</code>
  and calling delay on a class method written in my User model
  like:</p>
  
  <pre><code>delay.mass_invite_through_csv(mass_invitation.id, current_user, data)
  </code></pre>
  
  <p>here mass_invitation is a object of MassInvitation Class and current_user is current_user, and data is a hash params.</p>
  
  <p>now this method is getting executed infinitely.</p>
  
  <p>In my Procfile:</p>
  
  <pre><code>web: bundle exec rails server -p $PORT
  worker: bundle exec sidekiq -C config/sidekiq.yml
  </code></pre>
  
  <p>in my config/sidekiq.yml</p>
  
  <pre><code>concurrency:  3
  </code></pre>
  
  <p>everything is working correctly locally, please help.</p>