Test for traceback depth fails on Windows

[takluyver]

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FAIL: Test traceback offset in `ipython script.py`
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Traceback (most recent call last):
  File "S:\Users\slave\Jenkins\shiningpanda\jobs\671a3b23\virtualenvs\ff035a1d\lib\site-packages\nose\case.py", line 198, in runTest
    self.test(*self.arg)
  File "S:\Users\slave\Jenkins\shiningpanda\jobs\671a3b23\virtualenvs\ff035a1d\lib\site-packages\ipython-2.0.0_dev-py3.3.egg\IPython\core\tests\test_run.py", line 512, in test_script_tb
    nt.assert_in("RuntimeError", out)
nose.proxy.AssertionError: 'RuntimeError' not found in ''
    """Fail immediately, with the given message."""
>>  raise self.failureException("'RuntimeError' not found in ''")