Allow usage with PHP 5

Author: sgrodzicki

README.md

@@ -13,7 +13,7 @@ easy inclusion in your projects.
 ## Requirements
 
 - a server with:
-  - PHP 7.2 or higher 
+  - PHP 5.5.0 or higher 
   - PHP json and PHP cURL modules
   - tested on Apache 2.4 with PHP 5.6.1 and cURL 7.42.1 and with PHP 7.4.9 and cURL 7.68.0
 - direct network connectivity between this server and the host and port (usually TCP port 8443 or port 443 for 

composer.json

@@ -20,7 +20,7 @@
         }
     ],
     "require": {
-        "php": ">=7.2",
+        "php": ">=5.5.0",
         "ext-curl": "*",
         "ext-json": "*"
     },