refactor: move from io/ioutil to io and os package (#2236)

The io/ioutil package has been deprecated as of Go 1.16, see
https://golang.org/doc/go1.16#ioutil. This commit replaces the existing
io/ioutil functions with their new definitions in io and os packages.

Signed-off-by: Eng Zer Jun <engzerjun@gmail.com>

pkg/error/httperror.go

@@ -18,7 +18,7 @@ package error
 
 import (
 	"fmt"
-	"io/ioutil"
+	"io"
 	"net/http"
 	"strings"
 )
@@ -66,7 +66,7 @@ func MakeErrorFromHTTP(resp *http.Response) error {
 
 	msg := resp.Status
 	defer resp.Body.Close()
-	body, err := ioutil.ReadAll(resp.Body)
+	body, err := io.ReadAll(resp.Body)
 	if err == nil && len(body) > 0 {
 		msg = strings.TrimSpace(string(body))
 	}