Update a wallet with a new limit.

        @param the name of the wallet.
        @param the new value of the limit.
        @return a success string from the plans server.
        @raise ServerError via make_request.

def update_wallet(self, wallet_name, limit):
        """Update a wallet with a new limit.

        @param the name of the wallet.
        @param the new value of the limit.
        @return a success string from the plans server.
        @raise ServerError via make_request.
        """
        request = {
            'update': {
                'limit': str(limit),
            }
        }
        return make_request(
            '{}wallet/{}'.format(self.url, wallet_name),
            method='PATCH',
            body=request,
            timeout=self.timeout,
            client=self._client)