Premium Contao Theme Installation via Composer (WIP)

composer.json

{
    "name": "contao/managed-edition",
    "type": "project",
    "description": "Contao Open Source CMS",
    "license": "LGPL-3.0-or-later",
    "authors": [
        {
            "name": "Leo Feyer",
            "homepage": "https://github.com/leofeyer"
        }
    ],
    "require": {
        "php": "^7.2",
        "contao/calendar-bundle": "^4.4",
        "contao/comments-bundle": "^4.4",
        "contao/conflicts": "@dev",
        "contao/faq-bundle": "^4.4",
        "contao/listing-bundle": "^4.4",
        "contao/manager-bundle": "4.4.*",
        "contao/news-bundle": "^4.4",
        "contao/newsletter-bundle": "^4.4",
        "premium-contao-themes/eclipse": "dev-master"
    },
    "repositories": [
        {
            "type": "package",
            "package": {
                "name": "premium-contao-themes/eclipse",
                "type": "contao-module",
                "version": "dev-master",
                "dist": {
                    "type": "zip",
                    "url": "../eclipse.zip",
                    "reference": "master"
                },
                "require": {
                    "contao-community-alliance/composer-plugin": "^3.0"
                },
                "extra": {
                    "contao": {
                        "sources": {
                            "upload/system/modules/pct_autogrid": "system/modules/pct_autogrid",
                            "upload/system/modules/pct_customelements": "system/modules/pct_customelements",
                            "upload/system/modules/pct_iconpicker": "system/modules/pct_iconpicker",
                            "upload/system/modules/pct_megamenu": "system/modules/pct_megamenu",
                            "upload/system/modules/pct_revolutionslider": "system/modules/pct_revolutionslider",
                            "upload/system/modules/pct_themer": "system/modules/pct_themer",
                            "upload/templates": "templates/eclipse",
                            "upload/files/cto_layout": "files/cto_layout"
                        }
                    }
                }
            }
        }
    ],
    "conflict": {
        "contao-components/installer": "<1.3",
        "contao/core-bundle": "<4.4.8"
    },
    "extra": {
        "contao-component-dir": "assets"
    },
    "scripts": {
        "post-install-cmd": [
            "Contao\\ManagerBundle\\Composer\\ScriptHandler::initializeApplication"
        ],
        "post-update-cmd": [
            "Contao\\ManagerBundle\\Composer\\ScriptHandler::initializeApplication"
        ]
    }
}