added php download of membershipments

vendor/illuminate/contracts/Broadcasting/HasBroadcastChannel.php

@@ -0,0 +1,20 @@
+<?php
+
+namespace Illuminate\Contracts\Broadcasting;
+
+interface HasBroadcastChannel
+{
+    /**
+     * Get the broadcast channel route definition that is associated with the given entity.
+     *
+     * @return string
+     */
+    public function broadcastChannelRoute();
+
+    /**
+     * Get the broadcast channel name that is associated with the given entity.
+     *
+     * @return string
+     */
+    public function broadcastChannel();
+}