Lower symfony/var-dumper package requirements to ^3.0 instead of ^4.0

Author: hparadiz

composer.json

@@ -16,7 +16,7 @@
         "php": ">=7.1",
         "dwoo/dwoo": "1.3.6",
         "filp/whoops": "*",
-        "symfony/var-dumper": "^4.0"
+        "symfony/var-dumper": "^3.0"
     },
     "autoload": {
 	    "psr-4": {