Fix failing tests

Author: jasonmccreary

tests/fixtures/models/post-many-to-many-polymorphic-relationship.php

@@ -29,6 +29,6 @@ class Post extends Model
 
     public function tags()
     {
-        return $this->morphToMany(\App\Tag::class, 'tagable');
+        return $this->morphToMany(Tag::class, 'tagable');
     }
 }

tests/fixtures/models/tag-many-to-many-polymorphic-relationship.php

@@ -29,11 +29,11 @@ class Tag extends Model
 
     public function posts()
     {
-        return $this->morphedByMany(\App\Post::class, 'tagable');
+        return $this->morphedByMany(Post::class, 'tagable');
     }
 
     public function videos()
     {
-        return $this->morphedByMany(\App\Video::class, 'tagable');
+        return $this->morphedByMany(Video::class, 'tagable');
     }
 }

tests/fixtures/models/video-many-to-many-polymorphic-relationship.php

@@ -29,6 +29,6 @@ class Video extends Model
 
     public function tags()
     {
-        return $this->morphToMany(\App\Tag::class, 'tagable');
+        return $this->morphToMany(Tag::class, 'tagable');
     }
 }