async configure(config) {
        this.config = config;
        if (config.webhookSecret) {
            this.webhookSecret = config.webhookSecret;
            this.mode = 'local';
        }
    }
Configures the Stripe Webhook Manager.
@param {object} config
@param {string} [config.webhookSecret] An optional webhook secret for use with stripe-cli, passing this will ensure a webhook is not created in Stripe
@param {string} config.webhookHandlerUrl The URL which the Webhook should hit

@returns {Promise<void>}