Remove broken jsnext:main

Author: gaearon

package.json

@@ -3,7 +3,6 @@
   "version": "4.3.0",
   "description": "Official React bindings for Redux",
   "main": "./lib/index.js",
-  "jsnext:main": "./src/index.js",
   "scripts": {
     "build:lib": "babel src --out-dir lib",
     "build:umd": "cross-env NODE_ENV=development webpack src/index.js dist/react-redux.js",