test: add failing mastodon test (#3255)

* fix: refactor cache factory

* test: add failing test

* add null cache

tests/Bridges/MastodonBridgeTest.php

@@ -0,0 +1,17 @@
+<?php
+
+namespace RssBridge\Tests\Bridges;
+
+use PHPUnit\Framework\TestCase;
+
+class MastodonBridgeTest extends TestCase
+{
+    public function test()
+    {
+        \Configuration::loadConfiguration(['cache' => ['type' => 'null']]);
+        $b = new \MastodonBridge();
+        // https://bird.makeup/users/asmongold/remote_follow
+        $b->setDatas(['canusername' => '@asmongold@bird.makeup']);
+        $b->collectData();
+    }
+}