Added greet client

1. added greet client main.go
2. run, make clean; make greet
3. in one tab run,  ./bin/greet/server
4. in other tab run, ./bin/greet/client

greet/client/main.go

@@ -0,0 +1,19 @@
+package main
+
+import (
+	"log"
+
+	"google.golang.org/grpc"
+	"google.golang.org/grpc/credentials/insecure"
+)
+
+var addr string = "localhost:50051"
+
+func main() {
+	conn, err := grpc.Dial(addr, grpc.WithTransportCredentials(insecure.NewCredentials()))
+	if err != nil {
+		log.Fatalf("Failed to create connection: %v\n", err)
+	}
+	log.Println("Connected")
+	defer conn.Close()
+}