Bob Li

Results 4 issues of Bob Li

As issue #567 described. Copy the body buffer by buffer.Write to fix body mismatch with origin request when 307 or 308 redirect.

# Summary Resty [saved the request body's snapshot](https://github.com/go-resty/resty/blob/master/middleware.go#L521) for resending request with original HTTP method and body when http redirect such as 307 or 308 returned. Then in [http.Client.do](https://github.com/golang/go/blob/master/src/net/http/client.go#L661), golang...

![_5fa2d62b-b010-4334-b5c7-4ab5e3387913](https://user-images.githubusercontent.com/13741813/45676213-cff69400-bb63-11e8-93ef-5b6cfdf1f18c.png)

1. If *defer client.Close()* register before *if err != nil {*, panic will occur when disque is unable to access. 1. *pool.Get()* should retry after interval when *err != nil*