title: AttributeError: 'Config' object has no attribute 'test_system'
body: <pre><code>rootdir: python, inifile: pytest.ini, testpaths: test_cases
  plugins: metadata-1.8.0, html-1.22.0, sugar-0.9.2, timeout-1.3.3, forked-1.0.2, xdist-1.29.0, repeat-0.8.0
  timeout: 3600.0s
  timeout method: signal
  timeout func_only: False
  gw0 ok / gw1 ok / gw2 ok
  ../python-venv/lib/python2.7/site-packages/pluggy/hooks.py:289: in __call__
      return self._hookexec(self, self.get_hookimpls(), kwargs)
  ../python-venv/lib/python2.7/site-packages/pluggy/manager.py:87: in _hookexec
      return self._inner_hookexec(hook, methods, kwargs)
  ../python-venv/lib/python2.7/site-packages/pluggy/manager.py:81: in &lt;lambda&gt;
      firstresult=hook.spec.opts.get("firstresult") if hook.spec else False,
  ../python-venv/lib/python2.7/site-packages/_pytest/python.py:234: in pytest_pycollect_makeitem
      res = list(collector._genfunctions(name, obj))
  ../python-venv/lib/python2.7/site-packages/_pytest/python.py:410: in _genfunctions
      self.ihook.pytest_generate_tests(metafunc=metafunc)
  ../python-venv/lib/python2.7/site-packages/pluggy/hooks.py:289: in __call__
      return self._hookexec(self, self.get_hookimpls(), kwargs)
  ../python-venv/lib/python2.7/site-packages/pluggy/manager.py:87: in _hookexec
      return self._inner_hookexec(hook, methods, kwargs)
  ../python-venv/lib/python2.7/site-packages/pluggy/manager.py:81: in &lt;lambda&gt;
      firstresult=hook.spec.opts.get("firstresult") if hook.spec else False,
  ../../modules/test/python/test_cases/uts_plugin.py:20: in pytest_generate_tests
      for build_config in metafunc.config.test_system.build_configuration.get(
  E   AttributeError: 'Config' object has no attribute 'test_system'
  gw0 [1] / gw1 ok / gw2 ok
  </code></pre>
  
  <p>all tests are running fine without using "-n" option . I printed the attributes of config , and it does have test_system in it and i have no idea why it is failing .</p>