Fixed requirements for Symfony 3.4

Author: stof

composer.json

@@ -13,12 +13,12 @@
     "require": {
         "php": "^7.2",
         "symfony/asset": "^3.4.36 || ^4.3 || ^5.0",
-        "symfony/cache": "3.4.36 || ^4.3 || ^5.0",
-        "symfony/config": "3.4.36 || ^4.3 || ^5.0",
-        "symfony/dependency-injection": "3.4.36 || ^4.3 || ^5.0",
-        "symfony/finder": "3.4.36 || ^4.3 || ^5.0",
-        "symfony/framework-bundle": "3.4.36 || ^4.3 || ^5.0",
-        "symfony/http-kernel": "3.4.36 || ^4.3 || ^5.0"
+        "symfony/cache": "^3.4.36 || ^4.3 || ^5.0",
+        "symfony/config": "^3.4.36 || ^4.3 || ^5.0",
+        "symfony/dependency-injection": "^3.4.36 || ^4.3 || ^5.0",
+        "symfony/finder": "^3.4.36 || ^4.3 || ^5.0",
+        "symfony/framework-bundle": "^3.4.36 || ^4.3 || ^5.0",
+        "symfony/http-kernel": "^3.4.36 || ^4.3 || ^5.0"
     },
     "require-dev": {
         "symfony/phpunit-bridge": "^5.0"