Laravel Lumen PHPUnits [ReflectionException]类command.laracasts.seed不存在

Question

我正在运行一个基于Laravel Lumen的PHP项目 每当我运行测试套件（CodeCeption框架）时，都会在每次测试开始时（在artisan方法中运行$this->artisan("db:Seed");命令setup，并且得到以下信息错误：

  [ReflectionException] Class command.laracasts.seed does not exist  

#1  /app/vendor/illuminate/container/Container.php:753
#2  /app/vendor/illuminate/container/Container.php:631
#3  /app/vendor/illuminate/container/Container.php:586
#4  /app/vendor/laravel/lumen-framework/src/Application.php:230
#5  /app/vendor/illuminate/console/Application.php:228
#6  /app/vendor/illuminate/console/Application.php:242
#7  /app/vendor/illuminate/support/ServiceProvider.php:267
#8  /app/vendor/illuminate/console/Application.php:147
#9  /app/vendor/illuminate/console/Application.php:70
#10 /app/vendor/laravel/lumen-framework/src/Console/Kernel.php:165

有关信息，如果我一次运行一个测试类，则不会收到错误，而只有在运行测试套件时才得到此错误。