change type of attributes

Signed-off-by: Matthias Weirich <matthias.weirich@selectcode.de>

javascript/lib/api/src/model/things.model.ts

@@ -22,7 +22,7 @@ export class Thing extends EntityWithId {
 
   public constructor(private readonly _thingId: string,
     private readonly _policyId?: string,
-    private readonly _attributes?: object,
+    private readonly _attributes?: Record<string, any>,
     private readonly _features?: Features,
     private readonly __revision?: number,
     private readonly __modified?: string,