Add previous name.

        Args:
            :param name: previous name for the current author.
            :type name: string

def add_previous_name(self, name):
        """Add previous name.

        Args:
            :param name: previous name for the current author.
            :type name: string
        """
        self._ensure_field('name', {})
        self.obj['name'].setdefault('previous_names', []).append(name)