The `composer require` Command Fails

[astorm]

When trying to follow the installation instructions in the README.md, composer require extdn/extension-dashboard-m2 fails to install the extension due to (what looks like) a strange set of dependency conflicts.

My composer.json is included below. This composer.json file came from a composer create-project ... style installation and I've been using it as a testing instance for a number of years. In other words I think its pretty standard.

When the failure happened I tried deleting my vendor folder and re running composer install before running composer require extdn/extension-dashboard-m2 again with the same results.

Here's the errors

    $ composer require extdn/extension-dashboard-m2
    Using version dev-master for extdn/extension-dashboard-m2     
    ./composer.json has been updated
    Loading composer repositories with package information
    Updating dependencies (including require-dev)                 
    Your requirements could not be resolved to an installable set of packages.

      Problem 1
        - Conclusion: don't install composer/composer 1.8.4
        - Conclusion: don't install composer/composer 1.8.3
        - Conclusion: don't install composer/composer 1.8.2
        - Conclusion: don't install composer/composer 1.8.1
        - Conclusion: don't install composer/composer 1.8.0
        - Conclusion: don't install composer/composer 1.7.3
        - Conclusion: don't install composer/composer 1.7.2
        - Conclusion: don't install composer/composer 1.7.1
        - Conclusion: don't install composer/composer 1.7.0
        - Conclusion: don't install composer/composer 1.7.0-RC
        - Conclusion: don't install composer/composer 1.6.5
        - Conclusion: don't install composer/composer 1.6.4
        - Conclusion: don't install composer/composer 1.6.3
        - Conclusion: don't install composer/composer 1.6.2
        - Conclusion: don't install composer/composer 1.6.1
        - Conclusion: don't install composer/composer 1.6.0
        - Installation request for extdn/extension-dashboard-m2 dev-master -> satisfiable by extdn/extension-dashboard-m2[dev-master].
        - Installation request for magento/product-community-edition 2.2.0 -> satisfiable by magento/product-community-edition[2.2.0].
        - extdn/extension-dashboard-m2 dev-master requires magento/framework ^102.0.0 -> satisfiable by magento/framework[102.0.0-alpha79, 102.0.0-beta18, 102.0.0-beta23, 102.0.0-beta32, 102.0.0].
        - magento/framework 102.0.0 requires composer/composer ^1.6 -> satisfiable by composer/composer[1.6.0, 1.6.0-RC, 1.6.1, 1.6.2, 1.6.3, 1.6.4, 1.6.5, 1.7.0, 1.7.0-RC, 1.7.1, 1.7.2, 1.7.3, 1.8.0, 1.8.1, 1.8.2, 1.8.3, 1.8.4].
        - magento/framework 102.0.0-beta32 requires composer/composer ^1.6 -> satisfiable by composer/composer[1.6.0, 1.6.0-RC, 1.6.1, 1.6.2, 1.6.3, 1.6.4, 1.6.5, 1.7.0, 1.7.0-RC, 1.7.1, 1.7.2, 1.7.3, 1.8.0, 1.8.1, 1.8.2, 1.8.3, 1.8.4].
        - magento/framework 102.0.0-beta23 requires composer/composer ^1.6 -> satisfiable by composer/composer[1.6.0, 1.6.0-RC, 1.6.1, 1.6.2, 1.6.3, 1.6.4, 1.6.5, 1.7.0, 1.7.0-RC, 1.7.1, 1.7.2, 1.7.3, 1.8.0, 1.8.1, 1.8.2, 1.8.3, 1.8.4].
        - magento/framework 102.0.0-beta18 requires composer/composer ^1.6 -> satisfiable by composer/composer[1.6.0, 1.6.0-RC, 1.6.1, 1.6.2, 1.6.3, 1.6.4, 1.6.5, 1.7.0, 1.7.0-RC, 1.7.1, 1.7.2, 1.7.3, 1.8.0, 1.8.1, 1.8.2, 1.8.3, 1.8.4].
        - magento/framework 102.0.0-alpha79 requires composer/composer ^1.6 -> satisfiable by composer/composer[1.6.0, 1.6.0-RC, 1.6.1, 1.6.2, 1.6.3, 1.6.4, 1.6.5, 1.7.0, 1.7.0-RC, 1.7.1, 1.7.2, 1.7.3, 1.8.0, 1.8.1, 1.8.2, 1.8.3, 1.8.4].
        - Conclusion: don't install composer/composer 1.6.0-RC


    Installation failed, reverting ./composer.json to its original content.

and here's my composer.json

{
    "name": "magento/project-community-edition",
    "description": "eCommerce Platform for Growth (Community Edition)",
    "type": "project",
    "version": "2.2.0",
    "license": [
        "OSL-3.0",
        "AFL-3.0"
    ],
    "require": {
        "magento/product-community-edition": "2.2.0",
        "composer/composer": "@alpha",
        "rubic/magento2-module-clean-checkout": "^1.2",
        "magento/module-bundle-sample-data": "100.2.*",
        "magento/module-catalog-sample-data": "100.2.*",
        "magento/module-customer-sample-data": "100.2.*",
        "magento/module-theme-sample-data": "100.2.*",
        "magento/module-widget-sample-data": "100.2.*",
        "magento/module-cms-sample-data": "100.2.*",
        "magento/module-review-sample-data": "100.2.*",
        "magento/module-tax-sample-data": "100.2.*",
        "magento/module-msrp-sample-data": "100.2.*",
        "magento/module-sales-sample-data": "100.2.*",
        "magento/module-catalog-rule-sample-data": "100.2.*",
        "magento/module-configurable-sample-data": "100.2.*",
        "magento/module-product-links-sample-data": "100.2.*",
        "magento/module-wishlist-sample-data": "100.2.*",
        "magento/module-sales-rule-sample-data": "100.2.*",
        "magento/module-downloadable-sample-data": "100.2.*",
        "magento/module-grouped-product-sample-data": "100.2.*",
        "magento/module-swatches-sample-data": "100.2.*",
        "magento/sample-data-media": "100.2.*",
        "magento/module-offline-shipping-sample-data": "100.2.*"
    },
    "require-dev": {
        "phpunit/phpunit": "~6.2.0",
        "squizlabs/php_codesniffer": "3.0.1",
        "phpmd/phpmd": "@stable",
        "pdepend/pdepend": "2.5.0",
        "friendsofphp/php-cs-fixer": "~2.1.1",
        "lusitanian/oauth": "~0.8.10",
        "sebastian/phpcpd": "2.0.4"
    },
    "autoload": {
        "psr-4": {
            "Magento\\Framework\\": "lib/internal/Magento/Framework/",
            "Magento\\Setup\\": "setup/src/Magento/Setup/",
            "Magento\\": "app/code/Magento/"
        },
        "psr-0": {
            "": [
                "app/code/"
            ]
        },
        "files": [
            "app/etc/NonComposerComponentRegistration.php"
        ],
        "exclude-from-classmap": [
            "**/dev/**",
            "**/update/**",
            "**/Test/**"
        ]
    },
    "autoload-dev": {
        "psr-4": {
            "Magento\\Sniffs\\": "dev/tests/static/framework/Magento/Sniffs/",
            "Magento\\Tools\\": "dev/tools/Magento/Tools/",
            "Magento\\Tools\\Sanity\\": "dev/build/publication/sanity/Magento/Tools/Sanity/",
            "Magento\\TestFramework\\Inspection\\": "dev/tests/static/framework/Magento/TestFramework/Inspection/",
            "Magento\\TestFramework\\Utility\\": "dev/tests/static/framework/Magento/TestFramework/Utility/"
        }
    },
    "minimum-stability": "dev",
    "repositories": {
        "0": {
            "type": "composer",
            "url": "https://repo.magento.com/"
        },
        "extdndash": {
            "type": "git",
            "url": "https://github.com/extdn/extension-dashboard-m2.git"
        }
    },
    "extra": {
        "magento-force": "override"
    }
}

Looks like you are trying with Magento 2.2.0 - so far I have only developed on the latest 2.3.0. I'll add a note to the README to warn of this until I have had a chance to test this backwards.