Update vendor directory

vendor/github.com/aws/aws-sdk-go/aws/request/request.go

@@ -55,6 +55,8 @@ type Operation struct {
 	HTTPMethod string
 	HTTPPath   string
 	*Paginator
+
+	BeforePresignFn func(r *Request) error
 }
 
 // Paginator keeps track of pagination configuration for an API operation.
@@ -149,6 +151,15 @@ func (r *Request) SetReaderBody(reader io.ReadSeeker) {
 func (r *Request) Presign(expireTime time.Duration) (string, error) {
 	r.ExpireTime = expireTime
 	r.NotHoist = false
+
+	if r.Operation.BeforePresignFn != nil {
+		r = r.copy()
+		err := r.Operation.BeforePresignFn(r)
+		if err != nil {
+			return "", err
+		}
+	}
+
 	r.Sign()
 	if r.Error != nil {
 		return "", r.Error
@@ -334,6 +345,17 @@ func (r *Request) Send() error {
 	return nil
 }
 
+// copy will copy a request which will allow for local manipulation of the
+// request.
+func (r *Request) copy() *Request {
+	req := &Request{}
+	*req = *r
+	req.Handlers = r.Handlers.Copy()
+	op := *r.Operation
+	req.Operation = &op
+	return req
+}
+
 // AddToUserAgent adds the string to the end of the request's current user agent.
 func AddToUserAgent(r *Request, s string) {
 	curUA := r.HTTPRequest.Header.Get("User-Agent")