字典包含Date 数组，如何反序列化？

```
public struct Response: HandyJSON {
public init() {}
public init(days: [Date]) {
self.days = days
}
public var days: [Date] = []
}
```
如何指定 **Date** 转化 **ISO8601** 格式

目前不做处理，解析失败，返回了空数组

Start with the HandyJSON deserialization entry point for the Response example and trace how [Date] values are currently handled. Verify how an ISO8601 Date should be specified, then confirm that the days array is populated when the example JSON is parsed.

Written by the indexing model from the issue text.