Updates test to wait for results

fixes gh-1487

spring-cloud-gateway-core/src/test/java/org/springframework/cloud/gateway/discovery/DiscoveryClientRouteDefinitionLocatorIntegrationTests.java

@@ -19,7 +19,6 @@ package org.springframework.cloud.gateway.discovery;
 import java.util.List;
 import java.util.concurrent.atomic.AtomicBoolean;
 
-import org.junit.Ignore;
 import org.junit.Test;
 import org.junit.runner.RunWith;
 import reactor.core.publisher.Flux;
@@ -57,8 +56,7 @@ public class DiscoveryClientRouteDefinitionLocatorIntegrationTests {
 	private TestDiscoveryClient discoveryClient;
 
 	@Test
-	@Ignore
-	public void newServiceAddsRoute() {
+	public void newServiceAddsRoute() throws Exception {
 		List<Route> routes = routeLocator.getRoutes()
 				.filter(route -> route.getId().startsWith("test__")).collectList()
 				.block();
@@ -68,6 +66,8 @@ public class DiscoveryClientRouteDefinitionLocatorIntegrationTests {
 
 		publisher.publishEvent(new HeartbeatEvent(this, 1L));
 
+		Thread.sleep(2000);
+
 		routes = routeLocator.getRoutes()
 				.filter(route -> route.getId().startsWith("test__")).collectList()
 				.block();