Implemented WebHooks delivery queue.

Completely removed usage of the RabbitMQ. Queue now based on Redis channels.
Worker process now extracted as separate docker container.
Base image upgraded to the 1.8.0 version (PHP 7.2.7 and pcntl extension).

common/tasks/ClearAccountSessions.php

@@ -0,0 +1,64 @@
+<?php
+declare(strict_types=1);
+
+namespace common\tasks;
+
+use common\models\Account;
+use Yii;
+use yii\queue\RetryableJobInterface;
+
+class ClearAccountSessions implements RetryableJobInterface {
+
+    public $accountId;
+
+    public static function createFromAccount(Account $account): self {
+        $result = new static();
+        $result->accountId = $account->id;
+
+        return $result;
+    }
+
+    /**
+     * @return int time to reserve in seconds
+     */
+    public function getTtr(): int {
+        return 5 * 60;
+    }
+
+    /**
+     * @param int $attempt number
+     * @param \Exception|\Throwable $error from last execute of the job
+     *
+     * @return bool
+     */
+    public function canRetry($attempt, $error): bool {
+        return true;
+    }
+
+    /**
+     * @param \yii\queue\Queue $queue which pushed and is handling the job
+     * @throws \Exception
+     */
+    public function execute($queue): void {
+        $account = Account::findOne($this->accountId);
+        if ($account === null) {
+            return;
+        }
+
+        foreach ($account->getSessions()->each(100, Yii::$app->unbufferedDb) as $authSession) {
+            /** @var \common\models\AccountSession $authSession */
+            $authSession->delete();
+        }
+
+        foreach ($account->getMinecraftAccessKeys()->each(100, Yii::$app->unbufferedDb) as $key) {
+            /** @var \common\models\MinecraftAccessKey $key */
+            $key->delete();
+        }
+
+        foreach ($account->getOauthSessions()->each(100, Yii::$app->unbufferedDb) as $oauthSession) {
+            /** @var \common\models\OauthSession $oauthSession */
+            $oauthSession->delete();
+        }
+    }
+
+}