title: How to push job in specific queue and limit number workers with sidekiq?
body: <p>I know we can do:</p>
  
  <pre><code>sidekiq_options queue: "Foo"
  </code></pre>
  
  <p>But in this case it's the Worker which is assigned to only one queue: "Foo".</p>
  
  <p>I need to assign a Job (and not a Worker) in specific queue.
  With Resque it's easy: </p>
  
  <pre><code>Resque.enqueue_to(queue_name, my_job)
  </code></pre>
  
  <p>Further, for concurrency problem, i need to limit the number of Worker on each queue at 1. </p>
  
  <p>How can I do this?</p>