Add UserController to register/login users and api, register tests.

routes/api.php

@@ -28,6 +28,10 @@ Route::group([
         Route::apiResource('companies', CompanyController::class);
         Route::apiResource('categories', CategoryController::class);
         Route::apiResource('items', ItemController::class);
+
+        // User
+        Route::post('register', 'UserController@register');
+        Route::post('login', 'UserController@login');
     }
 );