Fixes for problems with starting and stopping apps in a minimal system

- Missing app dependencies
- Incorrect provider registrations
- Fatal execeptions thrown when external resources are not present

Change-Id: I3fdcf0666c88a47f399a722a9ab549d1104ff40e
diff --git a/apps/castor/BUILD b/apps/castor/BUILD
index 38b93ce..546453b 100644
--- a/apps/castor/BUILD
+++ b/apps/castor/BUILD
@@ -28,7 +28,10 @@
     category = "Utility",
     description = "Castor application",
     included_bundles = BUNDLES,
-    required_apps = ["org.onosproject.intentsynchronizer"],
+    required_apps = [
+        "org.onosproject.intentsynchronizer",
+        "org.onosproject.route-service",
+    ],
     title = "Castor",
     url = "http://onosproject.org",
 )