added testng import

src/test/java/com/example/demo/DemoApplicationTests.java

@@ -2,14 +2,11 @@ package com.example.demo;
 
 import static org.junit.Assert.assertTrue;
 
-import org.junit.Test;
-import org.junit.runner.RunWith;
-import org.junit.runners.JUnit4;
+import org.testng.annotations.Test;
 
 /**
  * Unit test for simple App.
  */
-@RunWith(JUnit4.class)
 public class DemoApplicationTests{
 
     @Test