2016-01-14 swift json http://qiita.com/dankogai/items/e3d9882f4d25bc44cc03 http://ja.stackoverflow.com/questions/3149/swift-nsurlsession-task%E3%81%8B%E3%82%89json-string-%E3%82%92%E8%BF%94%E3%81%99