Remove @Bean RestTemplate

(If users need one they can add it themselves)

Fixes gh-239

spring-cloud-sleuth-samples/spring-cloud-sleuth-sample-messaging/src/main/java/sample/SampleMessagingApplication.java

@@ -19,11 +19,13 @@ package sample;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.boot.SpringApplication;
 import org.springframework.boot.autoconfigure.SpringBootApplication;
+import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.EnableAspectJAutoProxy;
 import org.springframework.integration.annotation.IntegrationComponentScan;
 import org.springframework.scheduling.annotation.EnableAsync;
 import org.springframework.web.bind.annotation.RequestMapping;
 import org.springframework.web.bind.annotation.RestController;
+import org.springframework.web.client.RestTemplate;
 
 /**
  * @author Spencer Gibb
@@ -59,6 +61,11 @@ public class SampleMessagingApplication {
 		return this.transformer.send(msg);
 	}
 
+	@Bean
+	public RestTemplate restTemplate() {
+		return new RestTemplate();
+	}
+
 	public static void main(String[] args) {
 		SpringApplication.run(SampleMessagingApplication.class, args);
 	}