Add telegram bot handler.

tests/Monolog/Handler/TelegramBotHandlerTest.php

@@ -0,0 +1,42 @@
+<?php
+
+namespace Monolog\Handler;
+
+use Monolog\Logger;
+use Monolog\Test\TestCase;
+
+/**
+ * @author Mazur Alexandr <alexandrmazur96@gmail.com>
+ * @link https://core.telegram.org/bots/api
+ */
+class TelegramBotHandlerTest extends TestCase
+{
+    /**
+     * @var TelegramBotHandler
+     */
+    private $handler;
+
+    public function testSendTelegramRequest(): void
+    {
+        $this->createHandler();
+        $this->handler->handle($this->getRecord());
+    }
+
+    /**
+     * @param string $apiKey
+     * @param string $channel
+     */
+    private function createHandler(string $apiKey = 'testKey', string $channel = 'testChannel'): void
+    {
+        $constructorArgs = [$apiKey, $channel, Logger::DEBUG, true];
+
+        $this->handler = $this->getMockBuilder(TelegramBotHandler::class)
+            ->setConstructorArgs($constructorArgs)
+            ->setMethods(['send'])
+            ->getMock();
+
+        $this->handler->expects($this->atLeast(1))
+            ->method('send')
+            ->willReturn(null);
+    }
+}