support symfony4 (#59)

Author: daniel-iwaniec

composer.json

@@ -13,16 +13,16 @@
         "php":                 ">=5.5.9",
         "twig/twig":           "~1.23|~2.0",
         "twig/extensions":     "~1.0",
-        "symfony/twig-bridge": "~3.0",
-        "symfony/routing":     "~3.0",
-        "symfony/filesystem":  "~3.0",
-        "symfony/translation": "~3.0",
-        "symfony/form":        "~3.0",
-        "symfony/asset": "~2.8|~3.0"
+        "symfony/twig-bridge": "~3.0|~4.0",
+        "symfony/routing":     "~3.0|~4.0",
+        "symfony/filesystem":  "~3.0|~4.0",
+        "symfony/translation": "~3.0|~4.0",
+        "symfony/form":        "~3.0|~4.0",
+        "symfony/asset":  "~2.8|~3.0|~4.0"
     },
     "require-dev": {
-        "symfony/config":      "~3.0",
-        "phpunit/phpunit":     "~4.8"
+        "symfony/config":      "~3.0|~4.0",
+        "phpunit/phpunit":     "~4.8|~6.0"
     },
     "autoload": {
         "psr-0": { "Twig\\Gettext": "." }

phpunit.xml.dist

@@ -1,6 +1,7 @@
 <?xml version="1.0" encoding="UTF-8"?>
 
 <phpunit colors="true"
+         beStrictAboutTestsThatDoNotTestAnything="false"
          convertErrorsToExceptions="true"
          convertNoticesToExceptions="true"
          convertWarningsToExceptions="true"