test failure on ubuntu with python 2.7.11+

[mtholder]

This is hard to reproduce. It does not happen for me when I run the test alone, but If I add self.maxDiff = None to test_dataio_nexml_reader_tree_list.py and run it in the context of the full test suite, I get:

======================================================================
FAIL: test_collection_comments_and_annotations (dendropy.test.test_dataio_nexml_reader_tree_list.NexmlStandardTreeParsingTestCase)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/home/mtholder/Documents/projects/DendroPy/dendropy/test/test_dataio_nexml_reader_tree_list.py", line 61, in test_collection_comments_and_annotations
    expected_metadata)
  File "/home/mtholder/Documents/projects/DendroPy/dendropy/test/support/standard_file_test_trees.py", line 127, in compare_annotations_to_json_metadata_dict
    self.assertEqual(item_annotations_as_dict, expected_metadata)
AssertionError: {'Merycoidodon_%_$_permeant': 'envyingly247994 wagonload130853 ganglioneuron4665 [truncated]... != {u'$_demivotary_#_monumentlike': '31', u'!_missuggestion_frondivorous_#': 'False [truncated]...
- {'!_missuggestion_frondivorous_#': False,
+ {u'!_missuggestion_frondivorous_#': 'False',
?  +                                  +     +

-  '$_!_ichthyodorulite_birthplace': [-34.5128, 15.5375],
+  u'$_!_ichthyodorulite_birthplace': ['-34.5128', '15.5375'],
?  +                                   +        +  +       +

-  '$_demivotary_#_monumentlike': 31,
+  u'$_demivotary_#_monumentlike': '31',
?  +                               +  +

-  'Merycoidodon_%_$_permeant': 'envyingly247994 wagonload130853 ganglioneuron466526 horismology561695',
+  u'Merycoidodon_%_$_permeant': 'envyingly247994 wagonload130853 ganglioneuron466526 horismology561695',
?  +

-  'manganiferous_!_temulency_$': -26.8125}
+  u'manganiferous_!_temulency_$': '-26.8125'}
?  +                               +        +

[unode]

I'm getting this too on NixOS when adding dendropy. Here the error is perfectly reproducible:

======================================================================
FAIL: test_collection_comments_and_annotations (dendropy.test.test_dataio_nexml_reader_tree_list.NexmlStandardTreeParsingTestCase)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/dev/shm/nix-build-python2.7-DendroPy-4.3.0.drv-0/DendroPy-4.3.0/dendropy/test/test_dataio_nexml_reader_tree_list.py", line 60, in test_collection_comments_and_annotations
    expected_metadata)
  File "/dev/shm/nix-build-python2.7-DendroPy-4.3.0.drv-0/DendroPy-4.3.0/dendropy/test/support/standard_file_test_trees.py", line 127, in compare_annotations_to_json_metadata_dict
    self.assertEqual(item_annotations_as_dict, expected_metadata)
AssertionError: {'Merycoidodon_%_$_permeant': 'envyingly247994 wagonload130853 ganglioneuron4665 [truncated]... != {u'$_demivotary_#_monumentlike': '31', u'!_missuggestion_frondivorous_#': 'False [truncated]...
Diff is 796 characters long. Set self.maxDiff to None to see it.

Anything that can be done to prevent this test from failing?