Use voltha-protos version 4.0.2
Bump major version of voltha-lib-go to 4.0.0 as this change results
in incompatible API version compared to previous version

Change-Id: I1def58361fb1d85f07d6948ebf1ffb7a92eb0d4c
diff --git a/pkg/ponresourcemanager/ponresourcemanager_test.go b/pkg/ponresourcemanager/ponresourcemanager_test.go
index 0eab36e..b9ab649 100644
--- a/pkg/ponresourcemanager/ponresourcemanager_test.go
+++ b/pkg/ponresourcemanager/ponresourcemanager_test.go
@@ -20,9 +20,9 @@
 	"context"
 	"encoding/json"
 	"errors"
-	"github.com/opencord/voltha-lib-go/v3/pkg/db"
-	"github.com/opencord/voltha-lib-go/v3/pkg/db/kvstore"
-	"github.com/opencord/voltha-lib-go/v3/pkg/log"
+	"github.com/opencord/voltha-lib-go/v4/pkg/db"
+	"github.com/opencord/voltha-lib-go/v4/pkg/db/kvstore"
+	"github.com/opencord/voltha-lib-go/v4/pkg/log"
 	"github.com/stretchr/testify/assert"
 	"strings"
 	"testing"