Bump deps to ^4.4|^5.0 for Symfony 5.0

Author: nicolas-grekas

composer.json

@@ -24,11 +24,8 @@
         "symfony/http-kernel": ""
     },
     "require-dev": {
-        "symfony/http-foundation": "^3.4|^4.0|^5.0",
-        "symfony/http-kernel": "^4.3|^5.0"
-    },
-    "conflict": {
-        "symfony/http-kernel": "<4.3"
+        "symfony/http-foundation": "^4.4|^5.0",
+        "symfony/http-kernel": "^4.4|^5.0"
     },
     "autoload": {
         "psr-4": { "Symfony\\Component\\WebLink\\": "" },