use twig/twig instead of symfony/twig-bundle (#418)

* use twig/twig instead of symfony/twig-bundle

* use common conditional version signs

Author: ElectricMaxxx

composer.json

@@ -18,7 +18,7 @@
         "php": "^7.1",
         "symfony-cmf/routing": "^2.0",
         "symfony/framework-bundle": "^2.8 || ^3.3 || ^4.0",
-        "symfony/twig-bundle": "^2.8 || ^3.3 || ^4.0"
+        "twig/twig": "^1.35 || ^2.4.4"
     },
     "require-dev": {
         "doctrine/phpcr-odm": "^1.4|^2.0",