modified symfony version to be compatible from PS > 1.7

Author: GytisZum

composer.json

@@ -12,12 +12,12 @@
     }
   ],
   "require": {
-    "php": ">=7.2.0"
+    "php": ">=7.1.0"
   },
   "require-dev": {
     "phpunit/phpunit": "^5.7",
-    "symfony/lock": "^5.4",
-    "symfony/filesystem": "^5.4"
+    "symfony/lock": "v3.4.0",
+    "symfony/filesystem": "v3.4.0"
   },
   "autoload": {
     "psr-4": {