Allow cms-composer-installers 3.x (#4)

Author: gilbertsoft

composer.json

@@ -6,7 +6,7 @@
     "require": {
         "php": "^7.0",
         "helhum/typo3-console": "^5.8.3 || ^6.0",
-        "typo3/cms-composer-installers": "^1.4.2 || ^2.0"
+        "typo3/cms-composer-installers": "^1.4.2 || ^2.0 || ^3.0"
     },
     "autoload": {
         "psr-4": {