Update create.js

Author: underscore05

src/resolver/Mutation/create.js

@@ -1,7 +1,7 @@
 export default (entityData = []) => (_, entity) => {
     const newId =
         entityData.length > 0 ? entityData[entityData.length - 1].id + 1 : 0;
-    const newEntity = Object.assign(entity, { id: newId });
+    const newEntity = Object.assign({}, entity, { id: newId });
     entityData.push(newEntity);
     return newEntity;
 };