add trivial unit test for deployment - now to find how to make it work!

deployment/data-model-test.nix

@@ -180,14 +180,15 @@ in
       {
         inherit (fediversity)
           example-configuration
-          example-deployment
           ;
+        has-deployment = lib.isAttrs fediversity.example-deployment.resources.the-machine;
       };
     expected = {
       example-configuration = {
         enable = true;
         applications.hello.enable = true;
       };
+      has-deployment = true;
     };
   };
 }