title: How to run rspec tests in parallel for non-rails application
body: <p>I'm trying find out how to make rspec tests multithreaded.</p>
  
  <pre><code>describe 'Suite' do
    it 'first' do
      ...
    end
  
    it 'second', type: :thread do
      ...
    end
  
    it 'third', type: :thread do
      ...
    end
  end
  </code></pre>
  
  <p>In this case I want running tests in parallel which specified type as thread, non-specified type tests should be run in single thread. How Can I do that?</p>