failed to open stream: No such file or directory in /Users/user/Projects/Own/marketplacekit/artisan on line 18 code example

Example: failed to open stream: No such file or directory in artisan on line 18

The error is due to missing vendor folder.
You just need to run `composer install` in the project directory which will 
create a folder named vendor which will have all composer libraries and 
`autoload.php` file.