Chance PHP version requirement

Author: Mirobit

README.md

@@ -28,7 +28,7 @@ Check out [ElextrumX Dashboard](https://github.com/Mirobit/electrumx-dashboard)
 
 - Bitcoin Core 0.19.0.1+
 - Web Server (Apache, Nginx, PHP Server)
-- PHP 7.0.0+
+- PHP 7.3.0+
   - curl extension
 - Docker (Alternative to Web Server and PHP)
 

composer.json

@@ -18,7 +18,7 @@
   },
   "type": "project",
   "require": {
-    "php": "^7.0",
+    "php": "^7.3",
     "ext-curl": "*"
   }
 }