Merge pull request #39 from ElectricMaxxx/allow_symfony_4.0

allow symfony 4.0

Author: stloyd

composer.json

@@ -16,7 +16,7 @@
         "php": "^5.3|^7.0",
 
         "sebastian/exporter": "^1.0|^2.0",
-        "symfony/config": "^2.3|^3.0"
+        "symfony/config": "^2.3|^3.0|^4.0"
     },
     "require-dev": {
         "phpunit/phpunit": "^4.0|^5.0"