KeyError: 0 when running example about outlier-utils

[gitPrinz]

I switched the first two numbers, so it doesn't fail:

data = pd.Series([8, 1, 9, 10, 9])

But named rows

data = pd.Series({'a': 8, 'b': 1, 'c': 9, 'd': 10, 'e': 9})

give

Traceback (most recent call last):
  File "xxx\lib\site-packages\IPython\core\interactiveshell.py", line 3331, in run_code
    exec(code_obj, self.user_global_ns, self.user_ns)
  File "<ipython-input-37-4ecfcc731723>", line 1, in <module>
    grubbs.test(data, alpha=0.05)
  File "xxx\lib\site-packages\outliers\smirnov_grubbs.py", line 243, in test
    return two_sided_test(data, alpha)
  File "xxx\lib\site-packages\outliers\smirnov_grubbs.py", line 207, in two_sided_test
    return _two_sided_test(data, alpha, OutputType.DATA)
  File "xxx\lib\site-packages\outliers\smirnov_grubbs.py", line 195, in _two_sided_test
    return _test(TwoSidedGrubbsTest, data, alpha, output_type)
  File "xxx\lib\site-packages\outliers\smirnov_grubbs.py", line 191, in _test
    return test_class(data).run(alpha, output_type=output_type)
  File "xxx\lib\site-packages\outliers\smirnov_grubbs.py", line 127, in run
    data = self._delete_item(data, outlier_index)
  File "xxx\lib\site-packages\outliers\smirnov_grubbs.py", line 59, in _delete_item
    return data.drop(index)
  File "xxx\lib\site-packages\pandas\core\series.py", line 4139, in drop
    errors=errors,
  File "xxx\lib\site-packages\pandas\core\generic.py", line 3936, in drop
    obj = obj._drop_axis(labels, axis, level=level, errors=errors)
  File "xxx\lib\site-packages\pandas\core\generic.py", line 3970, in _drop_axis
    new_axis = axis.drop(labels, errors=errors)
  File "xxx\lib\site-packages\pandas\core\indexes\base.py", line 5017, in drop
    raise KeyError(f"{labels[mask]} not found in axis")
KeyError: '[1] not found in axis'

Maybe this is related?