Add ability to send link_names parameter in Slack notification

By default, leave link_names off. Added a method to enable link_names.

Signed-off-by: Donnie La Curan <don.lacuran@gmail.com>

src/Illuminate/Notifications/Channels/SlackWebhookChannel.php

@@ -59,6 +59,7 @@ protected function buildJsonPayload(SlackMessage $message)
             'icon_emoji' => data_get($message, 'icon'),
             'icon_url' => data_get($message, 'image'),
             'channel' => data_get($message, 'channel'),
+            'link_names' => data_get($message, 'linkNames'),
         ]);
 
         return array_merge([

src/Illuminate/Notifications/Messages/SlackMessage.php

@@ -48,6 +48,13 @@ class SlackMessage
      */
     public $content;
 
+    /**
+     * Linkify channel names and usernames.
+     *
+     * @var bool
+     */
+    public $linkNames = 0;
+
     /**
      * The message's attachments.
      *
@@ -98,6 +105,18 @@ public function error()
         return $this;
     }
 
+    /**
+     * Find and link channel names and usernames.
+     *
+     * @return $this
+     */
+    public function linkNames()
+    {
+        $this->linkNames = 1;
+
+        return $this;
+    }
+
     /**
      * Set a custom username and optional emoji icon for the Slack message.
      *