update dockerfile

Author: kingsley-einstein

package.json

@@ -9,7 +9,7 @@
     "client": "npm start --prefix frontend",
     "dev": "concurrently \"npm run server\" \"npm run client\"",
     "build:server": "tsc",
-    "build:frontend": "cd frontend && sudo yarn build"
+    "build:frontend": "cd frontend && npm run build"
   },
   "dependencies": {
     "@sendgrid/mail": "^7.6.1",