title: Error using pytest tutorial
body: <p>I read that unit-test is a brilliant feature to write better code and assert that the features of some target code stay the same. So I wanted to use it...</p>
  
  <p>I am using Anaconda on my Linux machine.</p>
  
  <p>I started using <code>pytest</code> by working through the manual's starter guide <a href="http://pytest.org/latest/getting-started.html" rel="nofollow">on their homepage</a>.
  After a successful installation there appears a first (unintended) error:</p>
  
  <pre><code>strpeter@linuxComputer:~$ py.test 
  ================================================== test session starts ===================================================
  platform linux2 -- Python 2.7.8 -- py-1.4.25 -- pytest-2.6.3
  collected 0 items / 1 errors 
  
  ========================================================= ERRORS =========================================================
  ___________________________________________________ ERROR collecting . ___________________________________________________
  anaconda/lib/python2.7/site-packages/py/_path/common.py:331: in visit
      for x in Visitor(fil, rec, ignore, bf, sort).gen(self):
  anaconda/lib/python2.7/site-packages/py/_path/common.py:377: in gen
      for p in self.gen(subdir):
  anaconda/lib/python2.7/site-packages/py/_path/common.py:377: in gen
      for p in self.gen(subdir):
  anaconda/lib/python2.7/site-packages/py/_path/common.py:377: in gen
      for p in self.gen(subdir):
  anaconda/lib/python2.7/site-packages/py/_path/common.py:377: in gen
      for p in self.gen(subdir):
  anaconda/lib/python2.7/site-packages/py/_path/common.py:367: in gen
      if p.check(dir=1) and (rec is None or rec(p))])
  anaconda/lib/python2.7/site-packages/_pytest/main.py:628: in _recurse
      ihook.pytest_collect_directory(path=path, parent=self)
  anaconda/lib/python2.7/site-packages/_pytest/main.py:166: in call_matching_hooks
      plugins = self.config._getmatchingplugins(self.fspath)
  anaconda/lib/python2.7/site-packages/_pytest/config.py:688: in _getmatchingplugins
      plugins += self._conftest.getconftestmodules(fspath)
  anaconda/lib/python2.7/site-packages/_pytest/config.py:521: in getconftestmodules
      mod = self.importconftest(conftestpath)
  anaconda/lib/python2.7/site-packages/_pytest/config.py:554: in importconftest
      self._onimport(mod)
  anaconda/lib/python2.7/site-packages/_pytest/config.py:674: in _onimportconftest
      self.pluginmanager.consider_conftest(conftestmodule)
  anaconda/lib/python2.7/site-packages/_pytest/core.py:201: in consider_conftest
      if self.register(conftestmodule, name=conftestmodule.__file__):
  anaconda/lib/python2.7/site-packages/_pytest/core.py:100: in register
      reg(plugin, name)
  anaconda/lib/python2.7/site-packages/_pytest/config.py:613: in _register_plugin
      call_plugin(plugin, "pytest_configure", {'config': self})
  anaconda/lib/python2.7/site-packages/_pytest/core.py:265: in call_plugin
      kwargs=kwargs, firstresult=True).execute()
  anaconda/lib/python2.7/site-packages/_pytest/core.py:315: in execute
      res = method(**kwargs)
  anaconda/lib/python2.7/site-packages/astropy/tests/pytest_plugins.py:78: in pytest_configure
      if not config.getoption('remote_data'):
  anaconda/lib/python2.7/site-packages/_pytest/config.py:836: in getoption
      raise ValueError("no option named %r" % (name,))
  E   ValueError: no option named u'remote_data'
                                                       DO *NOT* COMMIT!                                                     
  ================================================ 1 error in 2.77 seconds =================================================
  </code></pre>
  
  <p>I would like to understand where this stupid error comes from and how I can resolve it.
  Is the problem that I execute the program <code>py.test</code> without any filename and that there is no file called <code>__init.py__</code>?
  OK I am feeling really stupid by asking this question but please take the question serious since I found no hint in the world wide web.</p>