Change bad file path in express starting script (#24)

Author: bidoubiwa

examples/express/package.json

@@ -5,7 +5,7 @@
   "main": "index.js",
   "scripts": {
     "test": "jest",
-    "start": "node src/index.js"
+    "start": "node src/server.js"
   },
   "author": "",
   "license": "ISC",