User 모델에 has_many :posts 추가함
Event 모델에 has_one :plaza 추가함
Merge remote-tracking branch 'upstream/master' into develop

Conflicts:
	app/models/event.rb
User모델에 has_many :posts 관계선언 추가함
Merge pull request #65 from hschoidr/master

User 모델 관계선언 추가함