update react version.

Author: Saeki, Takahiro

package.json

@@ -35,7 +35,7 @@
     "babel-preset-react": "^6.5.0",
     "babel-preset-stage-0": "^6.5.0",
     "express": "^4.13.4",
-    "react": "^15.0.1",
+    "react": "^15.5.4",
     "react-dom": "^15.0.1",
     "react-transform-catch-errors": "^1.0.2",
     "react-transform-hmr": "^1.0.4",