Laravel BadMethodCallException Method getLogin does not exist

I am in the process of upgrading a CMS that was built on Laravel 5.1 to Laravel 5.5. I am getting the following error.

BadMethodCallException Method [getLogin] does not exist. in Controller.php (line 68) vendor\laravel\framework\src\Illuminate\Routing\Controller.php

Here are my routes. Any idea what is the issue?

Http\routes.php
Route::get('core/admin/login', 'Auth\AuthController@getLogin');
Route::post('core/admin/login', 'Auth\AuthController@postLogin');
Route::get('core/admin/logout', 'Auth\AuthController@getLogout');

via Chebli Mohamed