Change NPM scripts

- `npm run dev` to start dev mode
 - `npm start` to build production bundle and start the node server

=> Default to production with `npm start` and be explicit when
starting the dev server

README.md

@@ -8,9 +8,8 @@
 
 ## Development
 
-    npm start
+    npm run dev
 
 ## Server
 
-    npm run build
-    node server/index.js
+    npm start

package.json

@@ -13,9 +13,10 @@
     "react-router": "4.0.0-alpha.6"
   },
   "scripts": {
-    "start": "react-scripts start",
+    "dev": "react-scripts start",
     "build": "react-scripts build",
     "test": "react-scripts test --env=jsdom",
-    "eject": "react-scripts eject"
+    "eject": "react-scripts eject",
+    "start": "npm run build&&node server/index.js"
   }
 }