Merge pull request #713 from XWB/twig3

Allow Twig 3

Author: XWB

composer.json

@@ -37,7 +37,7 @@
         "symfony/validator": "~3.4|^4.3",
         "symfony/twig-bundle": "~3.4|^4.3",
         "symfony/twig-bridge": "~3.4|^4.3",
-        "twig/twig": "~2.0",
+        "twig/twig": "~2.0|~3.0",
         "phpoption/phpoption": "~1.1",
         "doctrine/annotations": "~1.0"
     },