Update composer files

Author: mpiot

composer.json

@@ -39,7 +39,7 @@
         "symfony/dom-crawler": "~3.4|~4.0",
         "symfony/polyfill-intl-icu": "~1.0",
         "symfony/security": "~3.4|~4.0",
-        "symfony/form": "~3.4|~4.0",
+        "symfony/form": "^4.1",
         "symfony/expression-language": "~3.4|~4.0",
         "symfony/process": "~3.4|~4.0",
         "symfony/security-core": "~3.4|~4.0",
@@ -65,7 +65,7 @@
         "phpunit/phpunit": "<4.8.35|<5.4.3,>=5.0",
         "symfony/asset": "<3.4",
         "symfony/console": "<3.4",
-        "symfony/form": "<3.4",
+        "symfony/form": "<4.1",
         "symfony/property-info": "<3.4",
         "symfony/serializer": "<4.1",
         "symfony/stopwatch": "<3.4",