vendor: update all dependencies

vendor/golang.org/x/oauth2/jwt/jwt.go

@@ -61,6 +61,11 @@ type Config struct {
 
 	// Expires optionally specifies how long the token is valid for.
 	Expires time.Duration
+
+	// Audience optionally specifies the intended audience of the
+	// request.  If empty, the value of TokenURL is used as the
+	// intended audience.
+	Audience string
 }
 
 // TokenSource returns a JWT TokenSource using the configuration
@@ -105,6 +110,9 @@ func (js jwtSource) Token() (*oauth2.Token, error) {
 	if t := js.conf.Expires; t > 0 {
 		claimSet.Exp = time.Now().Add(t).Unix()
 	}
+	if aud := js.conf.Audience; aud != "" {
+		claimSet.Aud = aud
+	}
 	h := *defaultHeader
 	h.KeyID = js.conf.PrivateKeyID
 	payload, err := jws.Encode(&h, claimSet, pk)