Upgrade to Reactor 3.0 and start building against SI 5.0 snapshots

Closes gh-7301
See gh-7029

spring-boot-cli/samples/reactor.groovy

@@ -1,48 +0,0 @@
-package org.test
-
-import java.util.concurrent.CountDownLatch
-
-@EnableReactor
-@Log
-class Runner implements CommandLineRunner {
-
-	@Autowired
-	EventBus eventBus
-
-	private CountDownLatch latch = new CountDownLatch(1)
-
-	@PostConstruct
-	void init() {
-		log.info "Registering consumer"
-	}
-
-	void run(String... args) {
-		eventBus.notify("hello", Event.wrap("Phil"))
-		log.info "Notified Phil"
-		latch.await()
-	}
-
-	@Bean
-	CountDownLatch latch() {
-		latch
-	}
-
-}
-
-@Consumer
-@Log
-class Greeter {
-
-	@Autowired
-	EventBus eventBus
-
-	@Autowired
-	private CountDownLatch latch
-
-	@Selector(value="hello")
-	void receive(String data) {
-		log.info "Hello ${data}"
-		latch.countDown()
-	}
-
-}