added UserEntity

src/main/java/com/example/demo/DemoApplication.java

@@ -7,6 +7,7 @@ import org.springframework.boot.autoconfigure.SpringBootApplication;
 public class DemoApplication {
 
 	public static void main(String[] args) {
+        System.out.println("Hello, World!");
 		SpringApplication.run(DemoApplication.class, args);
 	}
 

src/main/java/com/example/demo/domain/UserEntity.java

@@ -0,0 +1,4 @@
+package com.example.demo.domain;
+
+public class UserEntity {
+}