Add support for Spring Rabbit (via Spring AMQP) to Boot

- If RabbitTemplate is on the classpath, turn on autodetection.
- Create a RabbitTemplate, a Rabbit ConnectionFactory, and a RabbitAdmin is spring.rabbitmq.dynamic:true
- Enable some **spring.rabbitmq** properties like host, port, username, password, and dynamic
- Add tests to verify functionality
- Add Groovy CLI functionality. Base it on @EnableRabbitMessaging. Add spring-amqp to the path.
- Create rabbit.groovy test to prove it all works.
- Make Queue and TopicExchange top-level Spring beans in rabbit.groovy test script

spring-boot-cli/src/test/java/org/springframework/boot/cli/SampleIntegrationTests.java

@@ -24,11 +24,7 @@ import java.util.concurrent.Future;
 import java.util.concurrent.TimeUnit;
 
 import org.apache.ivy.util.FileUtil;
-import org.junit.After;
-import org.junit.Before;
-import org.junit.BeforeClass;
-import org.junit.Rule;
-import org.junit.Test;
+import org.junit.*;
 import org.springframework.boot.OutputCapture;
 import org.springframework.boot.cli.command.CleanCommand;
 import org.springframework.boot.cli.command.RunCommand;
@@ -196,4 +192,13 @@ public class SampleIntegrationTests {
 		FileUtil.forceDelete(new File("activemq-data")); // cleanup ActiveMQ cruft
 	}
 
+    @Test
+    @Ignore // this test requires RabbitMQ to be run, so disable it be default
+    public void rabbitSample() throws Exception {
+        start("samples/rabbit.groovy");
+        String output = this.outputCapture.getOutputAndRelease();
+        assertTrue("Wrong output: " + output,
+                output.contains("Received Greetings from Spring Boot via RabbitMQ"));
+    }
+
 }