allow symfony 4

Author: freekmurze

composer.json

@@ -19,9 +19,9 @@
         "php": "^7.0",
         "clue/stdio-react": "^1.0",
         "jolicode/jolinotif": "^1.2",
-        "symfony/console": "^3.0",
-        "symfony/process": "^3.0",
-        "symfony/yaml": "^3.0",
+        "symfony/console": "^3.0|^4.0",
+        "symfony/process": "^3.0|^4.0",
+        "symfony/yaml": "^3.0|^4.0",
         "yosymfony/resource-watcher": "^1.2"
     },
     "require-dev": {