Add test coverage for the SSH key endpoints

app/Transformers/Api/Client/UserSSHKeyTransformer.php

@@ -0,0 +1,26 @@
+<?php
+
+namespace Pterodactyl\Transformers\Api\Client;
+
+use Pterodactyl\Models\UserSSHKey;
+
+class UserSSHKeyTransformer extends BaseClientTransformer
+{
+    public function getResourceName(): string
+    {
+        return UserSSHKey::RESOURCE_NAME;
+    }
+
+    /**
+     * Return's a user's SSH key in an API response format.
+     */
+    public function transform(UserSSHKey $model): array
+    {
+        return [
+            'name' => $model->name,
+            'fingerprint' => $model->fingerprint,
+            'public_key' => $model->public_key,
+            'created_at' => $model->created_at->toIso8601String(),
+        ];
+    }
+}