Bump minimal requirements

Author: jderusse

composer.json

@@ -24,8 +24,8 @@
         "symfony/config": "^3.4.31|^4.3.4",
         "symfony/debug": "~2.8|~3.0|~4.0",
         "symfony/event-dispatcher": "~3.4|~4.0",
-        "symfony/http-foundation": "^3.3.11|~4.0",
-        "symfony/http-kernel": "~3.4|~4.0",
+        "symfony/http-foundation": "^3.4.13|~4.3",
+        "symfony/http-kernel": "^3.4.31|^4.3.4",
         "symfony/polyfill-mbstring": "~1.0",
         "symfony/filesystem": "~2.8|~3.0|~4.0",
         "symfony/finder": "~2.8|~3.0|~4.0",
@@ -40,7 +40,7 @@
         "symfony/css-selector": "~2.8|~3.0|~4.0",
         "symfony/dom-crawler": "~2.8|~3.0|~4.0",
         "symfony/polyfill-intl-icu": "~1.0",
-        "symfony/form": "^3.4.22|~4.1.11|^4.2.3",
+        "symfony/form": "^3.4.31|^4.3.4",
         "symfony/expression-language": "~2.8|~3.0|~4.0",
         "symfony/process": "~2.8|~3.0|~4.0",
         "symfony/security-core": "~3.2|~4.0",