Fixed most reported issues by SonarCloud.

module/src/test/java/com/iluwatar/module/AppTest.java

@@ -25,14 +25,17 @@ package com.iluwatar.module;
 
 import java.io.FileNotFoundException;
 import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.function.Executable;
+
+import static org.junit.jupiter.api.Assertions.assertDoesNotThrow;
 
 /**
  * Tests that Module example runs without errors.
  */
-public final class AppTest {
+final class AppTest {
 
   @Test
-  public void test() throws FileNotFoundException {
-    App.main();
+  void shouldExecuteWithoutException() {
+    assertDoesNotThrow((Executable) App::main);
   }
 }