Remove 'x-powered-by' header

src/server/index.js

@@ -26,6 +26,7 @@ createBackendSearchConfig().then(backendSearchConfig => {
   const app = express()
   app.set('port', process.env.PORT || DEFAULT_PORT)
   app.use(bodyParser.json())
+  app.disable('x-powered-by')
 
   // NODE_ENV is defined in package.json when running in localhost
   const isDevelopment = process.env.NODE_ENV === 'development'