Update composer.json

Author: richardhj

composer.json

@@ -21,11 +21,11 @@
     "source": "https://github.com/richardhj/contao-ajax_reload_element"
   },
   "require": {
-    "php": "^5.5 || ^7.0",
+    "php": ">=5.5",
     "contao/core-bundle": "^4.4",
     "contao-community-alliance/composer-plugin": "^3.0",
     "contao-community-alliance/url-builder": "^1.2",
-    "symfony/http-foundation": "^3.3 || ^4.0"
+    "symfony/http-foundation": "^3.3 || ^4.0 || ^5.0"
   },
   "autoload": {
     "psr-4": {