Update contracts.md

It looks like that the link to the Redis contract is broken for 5.4. I have submitted an edit that might fix that issue.

Author: ravigehlot

Diff for: contracts.md

@@ -192,7 +192,7 @@ Contract  |  References Facade
 [Illuminate\Contracts\Mail\Mailer](https://github.com/illuminate/contracts/blob/{{version}}/Mail/Mailer.php) | Mail
 [Illuminate\Contracts\Queue\Factory](https://github.com/illuminate/contracts/blob/{{version}}/Queue/Factory.php) | Queue::driver()
 [Illuminate\Contracts\Queue\Queue](https://github.com/illuminate/contracts/blob/{{version}}/Queue/Queue.php) | Queue
-[Illuminate\Contracts\Redis\Database](https://github.com/illuminate/contracts/blob/{{version}}/Redis/Database.php) | Redis
+[Illuminate\Contracts\Redis\Factory](https://github.com/illuminate/contracts/blob/{{version}}/Redis/Factory.php) | Redis
 [Illuminate\Contracts\Routing\Registrar](https://github.com/illuminate/contracts/blob/{{version}}/Routing/Registrar.php) | Route
 [Illuminate\Contracts\Routing\ResponseFactory](https://github.com/illuminate/contracts/blob/{{version}}/Routing/ResponseFactory.php) | Response
 [Illuminate\Contracts\Routing\UrlGenerator](https://github.com/illuminate/contracts/blob/{{version}}/Routing/UrlGenerator.php) | URL