use Guzzle in laravel package

I'm developing a package, and I need to request to external resource within that package. To do that, I need to require Guzzle in my library, I tried different ways, but it now working.

here is composer.json snippet.

"require": {
    "illuminate/support": "^5.1",
    "guzzlehttp/guzzle": "~5.0"
},

inside my package controller I tried something like that

use GuzzleHttp\Client as Guzzle;

and this way too.

use \GuzzleHttp\Client as Guzzle;

but all is I'm getting Reflection Exception

[ReflectionException]
  Class GuzzleHttp\Client does not exist

via Chebli Mohamed