Add fla back

sdk/nodejs/invoke.ts

@@ -34,4 +34,10 @@ export interface InvokeOptions {
      * invoke.
      */
     version?: string;
+
+    /**
+     * Invoke this function asynchronously.  If 'true' is passed in here, then an invoked function
+     * will only supply the `Promise<>` side of its result.
+     */
+    async?: boolean;
 }