Repository responsible to approach database queries of the categories
Inheritance: implements Fenos\Notifynder\Contracts\CategoryDB
 /** @test */
 function it_delete_a_category_by_name()
 {
     $categoryToDelete = $this->createCategory();
     $this->categoryRepo->deleteByName($categoryToDelete->name);
     $tryToFindThatCategory = $this->categoryRepo->findByName($categoryToDelete->name);
     $this->assertEquals($tryToFindThatCategory, null);
 }