거래 사진 업로드하
Merge commit 'd1517ee5a1813128a87056b39c36fea7e3f21963'

# By han
# Via ROR Lab. (1) and han (1)
* commit 'd1517ee5a1813128a87056b39c36fea7e3f21963':
  댓글기능 구현 완료.

Conflicts:
	app/models/bookkeeping.rb

해결함.