unittests errors

[sandrotosi]

Hello, I got these errors (they are for python3.5, but they are the same on 2.7 and 3.4):

FAIL: test_graph_with_shapefiles (__main__.TestGraphAPI)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "test/pydot_unittest.py", line 166, in test_graph_with_shapefiles
    self.assertEqual(hexdigest, hexdigest_original)
AssertionError: '570025288f29983b8793c9897fde68b4567cdcb54d2580a717d908b7c25ec83d' != '5c1ad2e74d62173ffc0f66efbf9e0ee4af2dbbd1383824984bf9a343947bac59'
- 570025288f29983b8793c9897fde68b4567cdcb54d2580a717d908b7c25ec83d
+ 5c1ad2e74d62173ffc0f66efbf9e0ee4af2dbbd1383824984bf9a343947bac59


======================================================================
FAIL: test_graphviz_regression_tests (__main__.TestGraphAPI)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "test/pydot_unittest.py", line 225, in test_graphviz_regression_tests
    self._render_and_compare_dot_files(REGRESSION_TESTS_DIR)
  File "test/pydot_unittest.py", line 252, in _render_and_compare_dot_files
    self.assertEqual(parsed_data_hexdigest, original_data_hexdigest)
AssertionError: '039cccb1fb1dd6e4a0381ebf34cc9712a3137179f466b027b847a382b46f88ac' != 'bb2aa7104b9a5e52e70331a1eb9ad028feafa9894e22b0e0195ed0194e047e58'
- 039cccb1fb1dd6e4a0381ebf34cc9712a3137179f466b027b847a382b46f88ac
+ bb2aa7104b9a5e52e70331a1eb9ad028feafa9894e22b0e0195ed0194e047e58