title: `rspec` with `spring` doesn't work
body: <p>I wanted to use <code>spring</code> instead of <code>spork</code>.</p>
  
  <p>I installed <code>spring</code> and <code>spring-commands-rspec</code>, and after installing I created binstubs by <code>bundle exec spring binstub --all</code>.</p>
  
  <p>When I run <code>bin/rspec</code>, I get only this result.</p>
  
  <pre><code>No examples found.
  
  
  Finished in 0.00099 seconds
  </code></pre>
  
  <p><code>bin/rake routes</code> gives me proper result. And <code>bundle exec rspec</code> tests all example I have like this.</p>
  
  <pre><code>Finished in 6.63 seconds
  20 examples, 2 failures, 11 pending
  
  Failed examples: 
  </code></pre>
  
  <p>What am I missing? Where should I configure the place of test directories?</p>