* uplift to latest expressive

src/App/Action/ActivitySignupAction.php

@@ -0,0 +1,29 @@
+<?php
+
+namespace App\Action;
+
+use App\Service\SkiesClientService;
+use Interop\Http\ServerMiddleware\DelegateInterface;
+use Interop\Http\ServerMiddleware\MiddlewareInterface as ServerMiddlewareInterface;
+use Psr\Http\Message\ServerRequestInterface;
+use Zend\Diactoros\Response\JsonResponse;
+
+class ActivitySignupAction implements ServerMiddlewareInterface
+{
+    /**
+     * @var SkiesClientService
+     */
+    private $skiesClient;
+
+    public function __construct(SkiesClientService $skiesClient)
+    {
+        $this->skiesClient = $skiesClient;
+    }
+
+    public function process(ServerRequestInterface $request, DelegateInterface $delegate)
+    {
+        $authHeader = $request->getHeaderLine("x-passthru-auth");
+        $id = $request->getAttribute("id");
+        return new JsonResponse($this->skiesClient->setAuthHeader($authHeader)->signUpActivity($id));
+    }
+}