Fix imports for e2e

pkg/signerverifier/gcp_test.go

@@ -2,6 +2,16 @@
 
 package signerverifier
 
+import (
+	"context"
+	"crypto/ecdsa"
+	"testing"
+
+	"github.com/docker/attest/internal/util"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
 const publicKeyPEM = `-----BEGIN PUBLIC KEY-----
 MFkwEwYHKoZIzj0CAQYIKoZIzj0DAQcDQgAEuMswW3iu7PR/rWTQjlhVmUsPK7rF
 k2s4SO3XbQ2GG2alm289SUUpmBAuVxvT8muYQ8HC/QzixzyTACTXsBDjQg==
@@ -12,7 +22,7 @@ k2s4SO3XbQ2GG2alm289SUUpmBAuVxvT8muYQ8HC/QzixzyTACTXsBDjQg==
 
 func TestGCPKMS_Signer(t *testing.T) {
 	// create a new signer
-	ctx := context.Background()
+	ctx := context.TODO()
 	ref := "projects/attest-kms-test/locations/us-west1/keyRings/attest-kms-test/cryptoKeys/test-signing-key/cryptoKeyVersions/1"
 	signer, err := GetGCPSigner(ctx, ref)
 	require.NoError(t, err)