Convert unicode string to ASCII.

        Credit: http://stackoverflow.com/a/517974

def _remove_accents(self, input_str):
        """
        Convert unicode string to ASCII.

        Credit: http://stackoverflow.com/a/517974
        """
        nkfd_form = unicodedata.normalize('NFKD', input_str)
        return u"".join([c for c in nkfd_form if not unicodedata.combining(c)])