Deprecate slackbot handler

src/Monolog/Handler/SlackbotHandler.php

@@ -16,8 +16,11 @@ use Monolog\Logger;
 /**
  * Sends notifications through Slack's Slackbot
  *
- * @author Haralan Dobrev <hkdobrev@gmail.com>
- * @see    https://slack.com/apps/A0F81R8ET-slackbot
+ * @author     Haralan Dobrev <hkdobrev@gmail.com>
+ * @see        https://slack.com/apps/A0F81R8ET-slackbot
+ * @deprecated According to Slack the API used on this handler it is deprecated.
+ *             Therefore this handler will be removed on 2.x
+ *             Slack suggests to use webhooks instead. Please contact slack for more information.
  */
 class SlackbotHandler extends AbstractProcessingHandler
 {
@@ -48,6 +51,7 @@ class SlackbotHandler extends AbstractProcessingHandler
      */
     public function __construct($slackTeam, $token, $channel, $level = Logger::CRITICAL, $bubble = true)
     {
+        @trigger_error('SlackbotHandler is deprecated and will be removed on 2.x', E_USER_DEPRECATED);
         parent::__construct($level, $bubble);
 
         $this->slackTeam = $slackTeam;