Update composer.json

Author: SpacePossum

composer.json

@@ -33,6 +33,7 @@
     "require-dev": {
         "psr/container": "^1.0",
         "symfony/finder": "~2.8|~3.0|~4.0",
+        "symfony/polyfill-ctype": "~1.8",
         "symfony/polyfill-intl-icu": "~1.0",
         "symfony/routing": "~2.8|~3.0|~4.0",
         "symfony/validator": "^3.2.5|~4.0",