Load Imagine class in Zend Framework 2

To load the class Imagine to a controller I executed the following line in the terminal: composer require imagine/imagine

Which, in the vendor folder, created a folder called imagine with many classes.

Then in the file "Module.php" of my controller I added the following function:

public function getServiceConfig()
{
    return array(
        'invokables' => array(
        'image_service' => 'Imagine\Gd\Imagine',
    ));
}

In my IndexController.php I place this line

$imagine = $this->getServiceLocator()->get('image_service');

And I get an error:

  

Zend \ ServiceManager \ ServiceManager :: createFromInvokable: failed   retrieving "imageservice (alias: image_service)" via invokable class   "Imagine \ Gd \ Imagine"; class does not exist

The most terrible thing is that my localhost works as well and does not give an error, but the server gives the error.