we have to be a wordpress-dropin after all

composer.json

 {
     "name": "lucha/r2db",
     "description": "r2db wordpress database",
-    "type": "library",
+    "type": "wordpress-dropin",
     "license": "MIT",
     "authors": [
         {
             "name": "lucha",
             "email": "lucha@paranoici.org"
         }
-    ]    
+    ],
+    "require": {
+        "composer/installers": "^1.9"
+    }
 }

composer.lock

@@ -4,39 +4,46 @@
         "Read more about it at https://getcomposer.org/doc/01-basic-usage.md#composer-lock-the-lock-file",
         "This file is @generated automatically"
     ],
-    "content-hash": "e52daa25e1055468071907a620892779",
+    "content-hash": "de2552fdb9aa51d1a6b58f116a6be25d",
     "packages": [
         {
-            "name": "flexihash/flexihash",
-            "version": "v2.0.2",
+            "name": "composer/installers",
+            "version": "v1.9.0",
             "source": {
                 "type": "git",
-                "url": "https://github.com/pda/flexihash.git",
-                "reference": "497ba5782606d998f8ab0b4e5942e3a799bec018"
+                "url": "https://github.com/composer/installers.git",
+                "reference": "b93bcf0fa1fccb0b7d176b0967d969691cd74cca"
             },
             "dist": {
                 "type": "zip",
-                "url": "https://api.github.com/repos/pda/flexihash/zipball/497ba5782606d998f8ab0b4e5942e3a799bec018",
-                "reference": "497ba5782606d998f8ab0b4e5942e3a799bec018",
+                "url": "https://api.github.com/repos/composer/installers/zipball/b93bcf0fa1fccb0b7d176b0967d969691cd74cca",
+                "reference": "b93bcf0fa1fccb0b7d176b0967d969691cd74cca",
                 "shasum": ""
             },
             "require": {
-                "php": ">=5.4.0"
+                "composer-plugin-api": "^1.0 || ^2.0"
+            },
+            "replace": {
+                "roundcube/plugin-installer": "*",
+                "shama/baton": "*"
             },
             "require-dev": {
-                "phpunit/phpunit": "^4.8",
-                "satooshi/php-coveralls": "~1.0",
-                "squizlabs/php_codesniffer": "^2.3",
-                "symfony/config": "^2.0.0",
-                "symfony/console": "^2.0.0",
-                "symfony/filesystem": "^2.0.0",
-                "symfony/stopwatch": "^2.0.0",
-                "symfony/yaml": "^2.0.0"
+                "composer/composer": "1.6.* || 2.0.*@dev",
+                "composer/semver": "1.0.* || 2.0.*@dev",
+                "phpunit/phpunit": "^4.8.36",
+                "sebastian/comparator": "^1.2.4",
+                "symfony/process": "^2.3"
+            },
+            "type": "composer-plugin",
+            "extra": {
+                "class": "Composer\\Installers\\Plugin",
+                "branch-alias": {
+                    "dev-master": "1.0-dev"
+                }
             },
-            "type": "library",
             "autoload": {
                 "psr-4": {
-                    "Flexihash\\": "src/"
+                    "Composer\\Installers\\": "src/Composer/Installers"
                 }
             },
             "notification-url": "https://packagist.org/downloads/",
@@ -45,19 +52,86 @@
             ],
             "authors": [
                 {
-                    "name": "Paul Annesley",
-                    "email": "paul@annesley.cc",
-                    "homepage": "http://paul.annesley.cc"
-                },
-                {
-                    "name": "Dom Morgan",
-                    "email": "dom@d3r.com",
-                    "homepage": "https://d3r.com"
+                    "name": "Kyle Robinson Young",
+                    "email": "kyle@dontkry.com",
+                    "homepage": "https://github.com/shama"
                 }
             ],
-            "description": "Flexihash is a small PHP library which implements consistent hashing",
-            "homepage": "https://github.com/pda/flexihash",
-            "time": "2016-04-22T21:03:23+00:00"
+            "description": "A multi-framework Composer library installer",
+            "homepage": "https://composer.github.io/installers/",
+            "keywords": [
+                "Craft",
+                "Dolibarr",
+                "Eliasis",
+                "Hurad",
+                "ImageCMS",
+                "Kanboard",
+                "Lan Management System",
+                "MODX Evo",
+                "MantisBT",
+                "Mautic",
+                "Maya",
+                "OXID",
+                "Plentymarkets",
+                "Porto",
+                "RadPHP",
+                "SMF",
+                "Thelia",
+                "Whmcs",
+                "WolfCMS",
+                "agl",
+                "aimeos",
+                "annotatecms",
+                "attogram",
+                "bitrix",
+                "cakephp",
+                "chef",
+                "cockpit",
+                "codeigniter",
+                "concrete5",
+                "croogo",
+                "dokuwiki",
+                "drupal",
+                "eZ Platform",
+                "elgg",
+                "expressionengine",
+                "fuelphp",
+                "grav",
+                "installer",
+                "itop",
+                "joomla",
+                "known",
+                "kohana",
+                "laravel",
+                "lavalite",
+                "lithium",
+                "magento",
+                "majima",
+                "mako",
+                "mediawiki",
+                "modulework",
+                "modx",
+                "moodle",
+                "osclass",
+                "phpbb",
+                "piwik",
+                "ppi",
+                "puppet",
+                "pxcms",
+                "reindex",
+                "roundcube",
+                "shopware",
+                "silverstripe",
+                "sydes",
+                "sylius",
+                "symfony",
+                "typo3",
+                "wordpress",
+                "yawik",
+                "zend",
+                "zikula"
+            ],
+            "time": "2020-04-07T06:57:05+00:00"
         }
     ],
     "packages-dev": [],