UnicodeDecodeError: 'ascii' codec can't decode byte 0xc3 in position 251

[jongra]

File "/tmp/pip-install-_blny4xr/Products.DateRecurringIndex/setup.py", line 12, in <module>
open('CONTRIBUTORS.rst').read(),

File "/lib/python3.6/encodings/ascii.py", line 26, in decodemodule>
return codecs.ascii_decode(input, self.errors)[0]
UnicodeDecodeError: 'ascii' codec can't decode byte 0xc3 in position 251: ordinal not in range(128)

Unfortunatly the CONTRIBUTORS.rst contain unicode characters which lead to an error in my case.
One could modify the python .read() function or the CONTRIBUTORS.rst.