public void Configure(IApplicationBuilder app, IApplicationEnvironment env) {
            Application.LoadFromEnvironment(env);

            // load config
            _config = new ConfigurationBuilder().AddEnvironmentVariables().Build();
            // load local config file if no environment variables
            var envn = _config.Get("env") ?? "local";
            if (envn == "local") {
                _config = new ConfigurationBuilder().AddJsonFile(env.ApplicationBasePath + "/config.local.json").Build();
            }
            Application.LoadFromConfig(_config);

            app.ForceHttps();
            app.Run(ProcessRequestAsync);
        }