Extra docs notions on updating to 5.7 (queue part)

Author: vv12131415

upgrade.md

@@ -422,6 +422,12 @@ If you have customized the default theme styles used for Markdown mailable templ
 
 The `QUEUE_DRIVER` environment variable has been renamed to `QUEUE_CONNECTION`. This should not affect existing applications that you are upgrading unless you intentionally modify your `config/queue.php` configuration file to match Laravel 5.7's.
 
+#### `stop-when-empty` option added to `WorkCommand`
+
+**Likelihood Of Impact: Very Low**
+
+`stop-when-empty` option was added to `WorkCommand`. If you extend this command, you need to add `stop-when-empty` to `$signature` property of your class.
+
 ### Routing
 
 #### The `Route::redirect` Method