title: Default skip test unless command line parameter present in py.test
body: <p>I have a long run test, which lasts 2 days, which I don't want to include in a usual test run. I also don't want to type command line parameters, that would deselect it and other tests at every usual test run. I would prefer to select a default-deselected test, when I actually need it. I tried renaming the test from <code>test_longrun</code> to <code>longrun</code> and use the command</p>
  
  <pre><code>py.test mytests.py::longrun
  </code></pre>
  
  <p>but that does not work.</p>