Merge commit 'eaca2e0ad3ddcbc3c51a77558afe148911a99525' into add_tag

# By doohee
# Via doohee
* commit 'eaca2e0ad3ddcbc3c51a77558afe148911a99525':
  Tag 기능 추
  Comments 기능 추가
로그인 유저가 아닐 경우의 Post 접근 시 비어있는 User  반환
Merge branch 'master' of https://github.com/dev-study/Project-Team-B

# Via Jaejin Gim
* 'master' of https://github.com/dev-study/Project-Team-B:
Merge pull request #10 from nije/master

Post 수정