MNT : retain 'replace' and 2.6 compat

Per https://docs.python.org/2/library/stdtypes.html#str.decode
the error handling arg was added in 2.2, but support for kwarg was
only added in 2.7

Author: tacaswell

lib/matplotlib/type1font.py

@@ -216,7 +216,7 @@ def _parse(self):
         # The spec calls this an ASCII format; in Python 2.x we could
         # just treat the strings and names as opaque bytes but let's
         # turn them into proper Unicode, and be lenient in case of high bytes.
-        convert = lambda x: x.decode('ascii')
+        convert = lambda x: x.decode('ascii', 'replace')
         for token, value in filtered:
             if token is self._name and value.startswith(b'/'):
                 key = convert(value[1:])