Convert initial version to @SpringBootApplication

initial/src/main/java/hello/Application.java

 import java.util.Arrays;
 
 import org.springframework.boot.SpringApplication;
-import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
 import org.springframework.context.ApplicationContext;
-import org.springframework.context.annotation.ComponentScan;
-import org.springframework.context.annotation.Configuration;
 
-@Configuration
-@EnableAutoConfiguration
-@ComponentScan
+@SpringBootApplication
 public class Application {
     
     public static void main(String[] args) {