Allow Symfony 4 components (#64)

Author: ostrolucky

composer.json

@@ -11,15 +11,15 @@
     "require": {
         "php": "^5.5 || ^7.0",
         "nikic/php-parser": "^3.0",
-        "symfony/finder": "^2.7 || ^3.0",
+        "symfony/finder": "^2.7 || ^3.0 || ^4.0",
         "twig/twig": "^1.27 || ^2.0",
         "doctrine/annotations": "^1.2"
     },
     "require-dev": {
         "phpunit/phpunit": "^4.8.36 || ^5.5 || ^6.2",
-        "symfony/translation": "^3.0",
-        "symfony/validator": "^2.7 || ^3.0",
-        "symfony/twig-bridge": "^3.0"
+        "symfony/translation": "^3.0 || ^4.0",
+        "symfony/validator": "^2.7 || ^3.0 || ^4.0",
+        "symfony/twig-bridge": "^3.0 || ^4.0"
     },
     "autoload": {
         "psr-4": {