Upgrade to laravel 5.1

app/Repositories/Category/CategoryRepository.php

@@ -48,7 +48,7 @@ class CategoryRepository extends ComponentRepository implements CategoryReposito
     {
         /** @var Collection $set */
         $set = Auth::user()->categories()->orderBy('name', 'ASC')->get();
-        $set->sortBy(
+        $set = $set->sortBy(
             function (Category $category) {
                 return $category->name;
             }

app/Repositories/Tag/TagRepository.php

@@ -109,7 +109,7 @@ class TagRepository implements TagRepositoryInterface
     {
         /** @var Collection $tags */
         $tags = Auth::user()->tags()->get();
-        $tags->sortBy(
+        $tags = $tags->sortBy(
             function (Tag $tag) {
                 return $tag->tag;
             }