RootController shows invalid value for AppInstanceController
Project: _spring-cloud-dataflow-server-core_

Billboard URL on **RootController**  `@RequestMapping("/")`:

`http://localhost:9393/`

The problematic part of it:

`{
"rel": "runtime/apps/instances",
"href": "http://localhost:9393/runtime/apps/interface%20org.springframework.web.util.UriComponents%24UriTemplateVariables/instances"
}`

According the code the **RootController** pass the **UriComponents.UriTemplateVariables.SKIP_VALUE** parameter to get the link for **AppInstanceStatusResource** class, but instead of it the `href` should be something like this:

`/runtime/apps/{appId}/instances`

This part `interface%20org.springframework.web.util.UriComponents%24UriTemplateVariables` is inserted into the placeholder for `{appId}`.

This problem appears in the following versions:
Local Dataflow Server: 1.2.3
Newer implementations and milestones: 1.3.0 M3
I did not try with older versions.
diff --git a/spring-cloud-dataflow-server-core/src/main/java/org/springframework/cloud/dataflow/server/controller/RootController.java b/spring-cloud-dataflow-server-core/src/main/java/org/springframework/cloud/dataflow/server/controller/RootController.java
index 5a7276f9f..c2ea71531 100644
--- a/spring-cloud-dataflow-server-core/src/main/java/org/springframework/cloud/dataflow/server/controller/RootController.java
+++ b/spring-cloud-dataflow-server-core/src/main/java/org/springframework/cloud/dataflow/server/controller/RootController.java
@@ -105,7 +105,7 @@ public class RootController {
 			root.add(unescapeTemplateVariables(
 					entityLinks.linkForSingleResource(AppStatusResource.class, "{appId}").withRel("runtime/apps/app")));
 			root.add(unescapeTemplateVariables(
-					entityLinks.linkFor(AppInstanceStatusResource.class, UriComponents.UriTemplateVariables.SKIP_VALUE)
+					entityLinks.linkFor(AppInstanceStatusResource.class, "{appId}")
 							.withRel("runtime/apps/instances")));
 			root.add(linkTo(MetricsController.class).withRel("metrics/streams"));
 		}
['spring-cloud-dataflow-server-core/src/main/java/org/springframework/cloud/dataflow/server/controller/RootController.java']