async cancelSubscription(id) {
        debug(`cancelSubscription(${id})`);
        try {
            await this._rateLimitBucket.throttle();
            const subscription = await this._stripe.subscriptions.del(id);
            debug(`cancelSubscription(${id}) -> Success`);
            return subscription;
        } catch (err) {
            debug(`cancelSubscription(${id}) -> ${err.type}`);
            throw err;
        }
    }
Cancel the Stripe Subscription by ID.

@param {string} id

@returns {Promise<ISubscription>}