fix lint issues (#179)

README.md

@@ -64,7 +64,7 @@ distribution of workload.
 The following code snippet shows just one connection.
 
 ```go
-conn, err := grpc.Dial("localhost:9080", grpc.WithInsecure())
+conn, err := grpc.Dial("localhost:9080", grpc.WithTransportCredentials(insecure.NewCredentials()))
 // Check error
 defer conn.Close()
 dgraphClient := dgo.NewDgraphClient(api.NewDgraphClient(conn))
@@ -74,7 +74,7 @@ The client can be configured to use gRPC compression:
 
 ```go
 dialOpts := append([]grpc.DialOption{},
-	grpc.WithInsecure(),
+	grpc.WithTransportCredentials(insecure.NewCredentials()),
 	grpc.WithDefaultCallOptions(grpc.UseCompressor(gzip.Name)))
 d, err := grpc.Dial("localhost:9080", dialOpts...)
 ```

examples_test.go

@@ -25,6 +25,7 @@ import (
 	"time"
 
 	"google.golang.org/grpc"
+	"google.golang.org/grpc/credentials/insecure"
 
 	"github.com/dgraph-io/dgo/v230"
 	"github.com/dgraph-io/dgo/v230/protos/api"
@@ -37,7 +38,7 @@ const (
 type CancelFunc func()
 
 func getDgraphClient() (*dgo.Dgraph, CancelFunc) {
-	conn, err := grpc.Dial(dgraphAddress, grpc.WithInsecure())
+	conn, err := grpc.Dial(dgraphAddress, grpc.WithTransportCredentials(insecure.NewCredentials()))
 	if err != nil {
 		log.Fatal("While trying to dial gRPC")
 	}