Upgrade to Gradle 6.8 and modernize the build

Closes gh-719

docs/src/test/java/com/example/restassured/ExampleApplicationJUnit5Tests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2014-2017 the original author or authors.
+ * Copyright 2014-2021 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -35,9 +35,9 @@ public class ExampleApplicationJUnit5Tests {
 
 	@BeforeEach
 	public void setUp(RestDocumentationContextProvider restDocumentation) {
-		this.spec = new RequestSpecBuilder()
-				.addFilter(documentationConfiguration(restDocumentation)) // <1>
+		this.spec = new RequestSpecBuilder().addFilter(documentationConfiguration(restDocumentation)) // <1>
 				.build();
 	}
 	// end::setup[]
+
 }