Recreated ExtensionTest.java

Author: amos1969

src/test/java/com/booleanuk/extension/ExtensionTest.java

@@ -0,0 +1,11 @@
+package com.booleanuk.extension;
+
+import org.junit.jupiter.api.Assertions;
+import org.junit.jupiter.api.Test;
+
+public class ExtensionTest {
+    @Test
+    public void shouldSayHelloWorld() {
+        Assertions.assertEquals("Hello, world!", Extension.sayHelloWorld());
+    }
+}