all: change module to google.golang.org/protobuf

Temporarily remove go.mod, since we can't generate an accurate one until
the corresponding v1 change is submitted.

Change-Id: I1e1ad97f2b455e33f61ffaeb8676289795e47e72
Reviewed-on: https://go-review.googlesource.com/c/protobuf/+/177000
Reviewed-by: Joe Tsai <thebrokentoaster@gmail.com>
diff --git a/proto/isinit_test.go b/proto/isinit_test.go
index 951b95f..232202f 100644
--- a/proto/isinit_test.go
+++ b/proto/isinit_test.go
@@ -8,10 +8,10 @@
 	"fmt"
 	"testing"
 
-	"github.com/golang/protobuf/v2/internal/scalar"
-	"github.com/golang/protobuf/v2/proto"
+	"google.golang.org/protobuf/internal/scalar"
+	"google.golang.org/protobuf/proto"
 
-	testpb "github.com/golang/protobuf/v2/internal/testprotos/test"
+	testpb "google.golang.org/protobuf/internal/testprotos/test"
 )
 
 func TestIsInitializedErrors(t *testing.T) {