Unable to read the ".env.local" environment file.

[tom-combet]

Describe the bug

When installing, GrumPHP throws following error:

PHP Fatal error: Uncaught _HumbugBox84aa00e62dca\Symfony\Component\Dotenv\Exception\PathException: Unable to read the ".env.local" environment file.

To Reproduce

1. Clone the repository
2. Run composer install

Expected behavior

Local environment file should be optional.

Screenshots

N/A

Additional context

GrumPHP doesn't allow optional environment files at the moment. I started a discussion to open a pull request.
But even so, we won't be able to update GrumPHP as long as we support PHP 7.

Hopefully, it's not a critical issue: you can fix it by creating empty .env.local file.