Added gosu to os dependencies

[sergiorodenas]

Gosu is needed for doing later command: ["gosu", "www-data", "/usr/local/bin/php", "artisan", "horizon"] as the
su version command: ["su", "www-data", "-c", "/usr/local/bin/php", "artisan", "horizon"] won't work due the www-data user having the login disabled internally.

[AlejandroAkbal]

Yeah, without this, using other user won't work, until it gets merged, this is a workaround:

Create a dockerfile with this

FROM serversideup/php:beta-${PHP_VERSION}-fpm-nginx

# TODO: Fix for gosu, remove when this is merged: https://github.com/serversideup/docker-php/pull/287
RUN docker-php-serversideup-dep-install-debian "gosu"

Compose:

    laravel-horizon:
        build:
          context: .
          dockerfile: Dockerfile
        command: ["gosu", "www-data", "/usr/local/bin/php", "artisan", "horizon"]

[jaydrogers]

Instead of the complexities with changing users, what do you think about this approach instead? #179 (comment)

[AlejandroAkbal]

This can now be closed