Update go dependencies

vendor/github.com/Azure/go-autorest/autorest/utility.go

@@ -20,6 +20,7 @@ import (
 	"encoding/xml"
 	"fmt"
 	"io"
+	"net/http"
 	"net/url"
 	"reflect"
 	"sort"
@@ -190,3 +191,14 @@ func createQuery(v url.Values) string {
 	}
 	return buf.String()
 }
+
+// ChangeToGet turns the specified http.Request into a GET (it assumes it wasn't).
+// This is mainly useful for long-running operations that use the Azure-AsyncOperation
+// header, so we change the initial PUT into a GET to retrieve the final result.
+func ChangeToGet(req *http.Request) *http.Request {
+	req.Method = "GET"
+	req.Body = nil
+	req.ContentLength = 0
+	req.Header.Del("Content-Length")
+	return req
+}