upgrade react-router in demo

package.json

@@ -95,7 +95,7 @@
     "react": "~0.14.1",
     "react-addons-test-utils": "~0.14.1",
     "react-dom": "~0.14.1",
-    "react-router": "1.0.0-rc3",
+    "react-router": "1.0.0-rc4",
     "webpack": "^1.10.1",
     "webpack-babel-jest": "^1.0.0",
     "webpack-dev-middleware": "^1.2.0"