Switch to Composer-based installation

[luckow]

Guess what:
https://docs.mautic.org/en/setup/switch-to-composer

Up until Mautic 4, users could download Mautic as a ZIP file and install it on any PHP server. [...] Next to that, Mautic recently introduced the Marketplace which isn't compatible with this installation method.

To be compatible with the Marketplace (and because the next major version of Mautic will use Composer as the default method), we should switch to the Composer-based installation in the app package.

I have no idea what that means in terms of time commitment, but I'm willing to test. Ping me if you need testers

[girish]

@luckow It already uses composer.

[luckow]

@girish
(Information from a Cloudron Mautic.app Backend)

[girish]

@luckow Oh thanks, we do use composer to install the deps. I think they want to install mautic itself via composer.