curl -X POST -H 'Content-Type:application/json' --data '{"author" : "jiwon", "title" : "this is title", "content": "this is content"}' http://localhost:8080/posts
curl -X POST -H 'Content-Type:application/json' --data '{"author" : "jiwon", "title" : "this is title", "content": "this is content"}' http://localhost:8080/posts