title: py.test passing results of one test to another
body: <p>Currently I have test looking like this:</p>
  
  <pre><code>@pytest.mark.parametrize("param", [1,2,3])
  def test_two_services(param):
      id = check_service_one(param)
      check_service_two(id)
  </code></pre>
  
  <p>Is there any way to split this test in two, where a second test depends on a first?</p>