Upgrade redux to 4.0.0-beta.2

Author: Wang Zhongliang

package.json

@@ -69,7 +69,7 @@
     "eslint-config-airbnb": "1.0.2",
     "eslint-plugin-react": "^4.1.0",
     "mocha": "^2.2.5",
-    "redux": "^3.4.0",
+    "redux": "4.0.0-beta.2",
     "rimraf": "^2.5.2",
     "typescript": "^1.8.10",
     "typescript-definition-tester": "0.0.4",