added skeleton validate script to composer

Author: jturbide

composer.json

@@ -185,6 +185,7 @@
     "zemit"
   ],
   "scripts": {
+    "skeleton": "vendor/bin/pds-skeleton validate ./",
     "phpunit": "vendor/bin/phpunit --config=phpunit.xml",
     "psalm": "vendor/bin/psalm --config=psalm.xml",
     "docs": "phpDocumentor -c phpdoc.xml"