Update to Symfony 4.1 #149 (#160)

* updated to Symfony 4.1 #149
* updated to phpunit 7 #149
* downgrade ocramius/proxy-manager for PHP 7.1 compatibility #149
* fixed symfony deprecations #149
* replaced AdvancedUserInterface with custom user checker
* code sniffer fixes

src/Security/UserChecker.php

@@ -0,0 +1,37 @@
+<?php
+
+/*
+ * This file is part of the Kimai time-tracking app.
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace App\Security;
+
+use App\Entity\User;
+use Symfony\Component\Security\Core\Exception\LockedException;
+use Symfony\Component\Security\Core\User\UserCheckerInterface;
+use Symfony\Component\Security\Core\User\UserInterface;
+
+/**
+ * Advanced checks during aithentication to make sure the user is allowed to use Kimai.
+ */
+class UserChecker implements UserCheckerInterface
+{
+    public function checkPreAuth(UserInterface $user)
+    {
+    }
+
+    public function checkPostAuth(UserInterface $user)
+    {
+        if (!$user instanceof User) {
+            return;
+        }
+
+        // user account is not enabled, the user may be notified
+        if (!$user->isEnabled()) {
+            throw new LockedException();
+        }
+    }
+}