Update composer.json

Author: Ilya Sakovich

composer.json

@@ -4,7 +4,7 @@
     "type": "library",
     "license": "MIT",
     "require": {
-        "php": ">=7.1",
+        "php": "^7.2",
         "ext-json": "*",
         "illuminate/support": "5.8.*|^6.0|^7.0"
     },