이벤트
RestAPI 구성 재정리 및 그에 따른 수정

-이벤트-
[get] /events
[get] /events/:id
[post] /events:id
[put]   /events/:id
[delete] /events:id

-이벤트 참석자-
[post]  /events/:id/participants

-이벤트 북마크-
[post]/events/:id/bookmarks
[delete]/events/:id/bookmarks/:userId

-이벤트 참가하기-
[post]/events/:id/attendances
[delete]/events/:id/attendances/:attendanceId

-이벤트 댓글-
[post]/events/:id/comments
[delete]/events/:id/comments/:commentsId

-이벤트 댓글의 댓글-
[post]/events/:id/comments/:commentId/reply
[delete]/events/:id/comments/:commentId/reply/:replyId
restAPI 정리