Uploads a signature for the invoice

        :param signature_dict: the signature
        :type signature_dict: dict
        :param invoice_id: the invoice id
        :return Response

def upload_invoice_signature(self, invoice_id, signature_dict):
        """
        Uploads a signature for the invoice

        :param signature_dict: the signature
        :type signature_dict: dict
        :param invoice_id: the invoice id
        :return Response
        """
        return self._create_put_request(
            resource=INVOICES,
            billomat_id=invoice_id,
            send_data=signature_dict,
            command=UPLOAD_SIGNATURE
        )