Add interface

Author: bastones

src/Interfaces/CustomFieldable.php

@@ -0,0 +1,13 @@
+<?php
+
+namespace Givebutter\LaravelCustomFields\Models;
+
+interface CustomFieldable
+{
+    /**
+     * Get the custom fields belonging to this model.
+     *
+     * @return mixed
+     */
+    public function customFields();
+}