Tweak Twig constraints to make sure we have namespaces

Author: bocharsky-bw

composer.json

@@ -22,7 +22,7 @@
         "php-translation/symfony-storage": "^1.0",
         "php-translation/extractor": "^1.6",
         "nyholm/nsa": "^1.1",
-        "twig/twig": "<1.39 || ^2.0,<2.8"
+        "twig/twig": "^1.38,<1.39 || ^2.7,<2.8"
     },
     "require-dev": {
         "symfony/phpunit-bridge": "^4.2",