added php download of membershipments

vendor/illuminate/contracts/Database/Eloquent/Castable.php

@@ -0,0 +1,15 @@
+<?php
+
+namespace Illuminate\Contracts\Database\Eloquent;
+
+interface Castable
+{
+    /**
+     * Get the name of the caster class to use when casting from / to this cast target.
+     *
+     * @param  array  $arguments
+     * @return string
+     * @return string|\Illuminate\Contracts\Database\Eloquent\CastsAttributes|\Illuminate\Contracts\Database\Eloquent\CastsInboundAttributes
+     */
+    public static function castUsing(array $arguments);
+}