[Falcon][WIP] CORD-368 Added APIs for service dependency

- Added create/remove service dependency to CordVtn
- Added new type for service ID

Change-Id: If836ab6bcc5e60c1707b2dbf0a244a204529b007
diff --git a/src/main/java/org/onosproject/cordvtn/CordVtnService.java b/src/main/java/org/onosproject/cordvtn/CordVtnService.java
index 5ab7baf..7bbc1e3 100644
--- a/src/main/java/org/onosproject/cordvtn/CordVtnService.java
+++ b/src/main/java/org/onosproject/cordvtn/CordVtnService.java
@@ -65,4 +65,20 @@
      * @return list of nodes
      */
     List<CordVtnNode> getNodes();
+
+    /**
+     * Creates a dependency between two services.
+     *
+     * @param tenantServiceId id of the service which has a dependency
+     * @param providerServiceId id of the service which provides dependency
+     */
+    void createServiceDependency(ServiceId tenantServiceId, ServiceId providerServiceId);
+
+    /**
+     * Removes a dependency between two services.
+     *
+     * @param tenantServiceId id of the service which has a dependency
+     * @param providerServiceId id of the service which provides dependency
+     */
+    void removeServiceDependency(ServiceId tenantServiceId, ServiceId providerServiceId);
 }