Revert "Add polyfill for Symbol.asyncIterator (reduxjs#1642)" (reduxj…

…s#1645)

* Revert "Add polyfill for Symbol.asyncIterator (reduxjs#1642)"

This reverts commit 3c976c5.

* Create silly-windows-flow.md

src/devTools.ts

@@ -1,6 +1,3 @@
-(Symbol as any).asyncIterator =
-  Symbol.asyncIterator || Symbol.for('Symbol.asyncIterator');
-
 import { stringify, parse } from 'jsan';
 import socketClusterClient, { AGClientSocket } from 'socketcluster-client';
 import configureStore from './configureStore';