fix relationships

Author: ilvalerione

src/Fields/Field.php

@@ -128,7 +128,7 @@ public function resolve($request, $model)
     /**
      * Define the callback that should be used to resolve the field's value.
      *
-     * @param  callable  $resolveCallback($modelAttribute)
+     * @param  callable  $resolveCallback($request, $modelAttribute)
      * @return $this
      */
     public function resolveUsing(callable $resolveCallback)

src/Http/Controllers/RelationshipController.php

@@ -10,7 +10,7 @@ class RelationshipController extends Controller
     public function get(RelationshipRequest $request)
     {
         return $request->findResourceOrFail()
-            ->resolvesRelationship($request);
+            ->resolvesRelationship($request)->value;
     }
 
     public function attach(RelationshipRequest $request)

src/ResolvesRelationships.php

@@ -44,9 +44,7 @@ public function resolvesRelationship($request)
                 return $item->name == $request->route('relationship');
             });
 
-        $relationship->resolve($request, $this->resource);
-
-        return $relationship->jsonSerialize();
+        return tap($relationship)->resolve($request, $this->resource);
     }
 
     /**