sendgrid integration with Laravel 5.2

I am working on a Laravel application which requires to send emails via sendgrid.com. I am trying to integrate this into my project but I am stuck at one place. I following the instructions given over here.

I am following for Laravel version 5.1~.

When I am adding following lines to my bootstrap/app.php,

$app->configure('mail');
$app->configure('services');
$app->register(Sichikawa\LaravelSendgridDriver\MailServiceProvider::class);

unset($app->availableBindings['mailer']);

my application fails to load the root page of application and my Chrome browser says "The page isn’t working". There is no output to laravel.log even.

However when I try to remove these lines I get the following error:

And this is the content of my laravel.log file:

[2016-06-03 12:07:25] production.ERROR: exception 'Symfony\Component\Debug\Exception\FatalErrorException' with message 'Class 'Sichikawa\LaravelSendgridDriver\MailServiceProvider' not found' in /home/oadmin/public_html/dev/http://ift.tt/1UlsCwi Stack trace:

0 {main}

What is the problem with my code? Can anybody please suggest me the way out.

Thank you.

via Chebli Mohamed