Bump to Buildah v1.13.1

Signed-off-by: TomSweeneyRedHat <tsweeney@redhat.com>

vendor/github.com/pkg/errors/errors.go

@@ -82,7 +82,7 @@
 //
 //     if err, ok := err.(stackTracer); ok {
 //             for _, f := range err.StackTrace() {
-//                     fmt.Printf("%+s:%d", f)
+//                     fmt.Printf("%+s:%d\n", f, f)
 //             }
 //     }
 //
@@ -159,6 +159,9 @@ type withStack struct {
 
 func (w *withStack) Cause() error { return w.error }
 
+// Unwrap provides compatibility for Go 1.13 error chains.
+func (w *withStack) Unwrap() error { return w.error }
+
 func (w *withStack) Format(s fmt.State, verb rune) {
 	switch verb {
 	case 'v':
@@ -241,6 +244,9 @@ type withMessage struct {
 func (w *withMessage) Error() string { return w.msg + ": " + w.cause.Error() }
 func (w *withMessage) Cause() error  { return w.cause }
 
+// Unwrap provides compatibility for Go 1.13 error chains.
+func (w *withMessage) Unwrap() error { return w.cause }
+
 func (w *withMessage) Format(s fmt.State, verb rune) {
 	switch verb {
 	case 'v':
@@ -254,29 +260,3 @@ func (w *withMessage) Format(s fmt.State, verb rune) {
 		io.WriteString(s, w.Error())
 	}
 }
-
-// Cause returns the underlying cause of the error, if possible.
-// An error value has a cause if it implements the following
-// interface:
-//
-//     type causer interface {
-//            Cause() error
-//     }
-//
-// If the error does not implement Cause, the original error will
-// be returned. If the error is nil, nil will be returned without further
-// investigation.
-func Cause(err error) error {
-	type causer interface {
-		Cause() error
-	}
-
-	for err != nil {
-		cause, ok := err.(causer)
-		if !ok {
-			break
-		}
-		err = cause.Cause()
-	}
-	return err
-}