Edit.php

<?php
namespace Surething\Testimonials\Controller\Adminhtml\TestimonialsImport;

class Edit extends \Magento\Backend\App\Action {

    public function execute() {

        $model = $this->_objectManager->create('Surething\Testimonials\Model\Testimonials');

        $registryObject = $this->_objectManager->get('Magento\Framework\Registry');
        $registryObject->register('testimonials_testimonials', $model);

        $this->_view->loadLayout();
        $this->_view->getLayout()->initMessages();
        $this->_view->renderLayout();
    }
}