Body of notification not sent

[Christer Lindh]

In Notification::jsonSerialize there is an error, causing "body" not to be added to jsonData if there is no title set

public function jsonSerialize()
    {
...
        if ($this->title) {
            $jsonData['body'] = $this->body;
        }

[johann59]

Hi I'll think it's because you have the same test for title and body,
a PR will be here if you want :)

#13