Pass CI build from GitHub Actions instead of Jenkins

The initial folder was missing the Application class so a
version was copied from the complete folder so that builds pass.
The files required for Jenkins builds were removed as the project
will migrate to GitHub Actions for CI.

initial/src/main/java/hello/Application.java

@@ -0,0 +1,12 @@
+package hello;
+
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+
+@SpringBootApplication
+public class Application {
+
+	public static void main(String[] args) {
+		SpringApplication.run(Application.class, args);
+	}
+}