Attachment model and database changes.

app/Models/TransactionJournal.php

@@ -467,6 +467,14 @@ class TransactionJournal extends Model
         $this->attributes['encrypted']   = true;
     }
 
+    /**
+     * @return \Illuminate\Database\Eloquent\Relations\MorphMany
+     */
+    public function attachments()
+    {
+        return $this->morphMany('App\Models\Attachment', 'attachable');
+    }
+
     /**
      * @codeCoverageIgnore
      * @return \Illuminate\Database\Eloquent\Relations\BelongsTo