pens_test.py: fix test failure with latest defcon

somehow the segmentType of the first move point of a contour is a unicode string now, and the test was comparing the repr...

tests/pens_test.py

@@ -17,6 +17,8 @@ class _TestPenMixin(object):
     PointPen test cases, plus some helper methods.
     """
 
+    maxDiff = None
+
     def diff(self, expected, actual):
         import difflib
         expected = str(self.Glyph(expected)).splitlines(True)

tests/utils.py

@@ -50,7 +50,7 @@ class DummyPointPen(BaseDummyPen):
         self.commands.append(('endPath', tuple(), {}))
 
     def addPoint(self, pt, segmentType=None, smooth=False, name=None, **kwargs):
-        kwargs['segmentType'] = segmentType
+        kwargs['segmentType'] = str(segmentType) if segmentType else None
         kwargs['smooth'] = smooth
         kwargs['name'] = name
         self.commands.append(('addPoint', (pt,), kwargs))