update minimal PHP version dependency

Author: agrzegorzewski

composer.json

@@ -12,7 +12,7 @@
         }
     ],
     "require": {
-        "php": ">=5.5",
+        "php": ">=7.2",
         "bugsnag/bugsnag": "^3.29.0",
         "symfony/config": "^2.7|^3|^4|^5|^6|^7|^8",
         "symfony/console": "^2.7|^3|^4|^5|^6|^7|^8",