Can not use the @RequestBody annotation and get the standard Whitelabel Error Page on my localhost:8080

import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestBody;
import org.springframework.web.bind.annotation.RequestMapping;

/**
 * Created by Christiaan on 27/05/2016.
 */

@Controller
public class GifController {
        @RequestMapping("/")
        @RequestBody
        public String listGifs() {
            return "List of all the Gifs";
        }
}

package com.kpqventures.giflib;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
import org.springframework.context.annotation.ComponentScan;

/**
 * Created by Christiaan on 26/05/2016.
 */

@EnableAutoConfiguration
@ComponentScan
public class AppConfig {
    public static void main(String [] args) {
        SpringApplication.run(AppConfig.class, args);
    }
}

buildscript {
    repositories {
        mavenCentral()
    }
    dependencies {
        classpath("org.springframework.boot:spring-boot-gradle-plugin:1.3.5.RELEASE")
    }
}

apply plugin: 'java'
apply plugin: 'eclipse'
apply plugin: 'idea'
apply plugin: 'spring-boot'

jar {
    baseName = 'gs-spring-boot'
    version =  '0.1.0'
}

repositories {
    mavenCentral()
}

sourceCompatibility = 1.8
targetCompatibility = 1.8

dependencies {
    // tag::jetty[]
    compile("org.springframework.boot:spring-boot-starter-web") {
        exclude module: "spring-boot-starter-tomcat"
    }
    compile("org.springframework.boot:spring-boot-starter-jetty")
    // end::jetty[]
    // tag::actuator[]
    compile("org.springframework.boot:spring-boot-starter-actuator")
    // end::actuator[]
    testCompile("junit:junit")
}

task wrapper(type: Wrapper) {
    gradleVersion = '2.3'
}