firebase sdk 연동
https://firebase.google.com/docs/web/setup?authuser=0
sdk config 작성
https://firebase.google.com/docs/web/learn-more?authuser=0#config-object
messeging end point
알림 보내는 api end point
https://firebase.google.com/docs/web/learn-more?authuser=0#config-object
떠돌이 생활을 하는. 실업자, 부랑 생활을 하는