constructor({url, env, serverConfig}) {
        this.url = url;
        this.env = env;
        this.serverConfig = serverConfig;

        this.rootApp = null;
        this.httpServer = null;

        // Tasks that should be run before the server exits
        this.cleanupTasks = [];
    }
@param {Object}  options
@param {String}  options.url
@param {String}  options.env development|production|testing
@param {Object}  options.serverConfig
@param {String}  options.serverConfig.host
@param {Number}  options.serverConfig.port
@param {Number}  options.serverConfig.shutdownTimeout
@param {Boolean} options.serverConfig.testmode