invocation: round of cleanups/fixes

token/invocation/schema_test.go

@@ -8,9 +8,10 @@ import (
 	"github.com/libp2p/go-libp2p/core/crypto"
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
+	"gotest.tools/v3/golden"
+
 	"github.com/ucan-wg/go-ucan/token/internal/envelope"
 	"github.com/ucan-wg/go-ucan/token/invocation"
-	"gotest.tools/v3/golden"
 )
 
 const (
@@ -78,6 +79,7 @@ func TestSchemaRoundTrip(t *testing.T) {
 		assert.JSONEq(t, string(invocationJson), readJson.String())
 	})
 }
+
 func privKey(t require.TestingT, privKeyCfg string) crypto.PrivKey {
 	privKeyMar, err := crypto.ConfigDecodeKey(privKeyCfg)
 	require.NoError(t, err)