Update npm script for heroku

Author: timiscoding

server/package.json

@@ -4,7 +4,7 @@
   "description": "",
   "main": "index.js",
   "scripts": {
-    "start": "cross-env NODE_ENV=production node index.js",
+    "start": "node index.js",
     "watch": "cross-env NODE_ENV=development nodemon index.js",
     "test": "cross-env NODE_ENV=test jest --verbose --runInBand",
     "test:debug": "cross-env NODE_ENV=test node --inspect-brk node_modules/.bin/jest tests/blog_api.test.js --runInBand"