Update README.md

Author: prisis

README.md

@@ -1,7 +1,7 @@
 <h1 align="center">Narrowspark Automatic Prefetcher</h1>
 <p align="center">
     <a href="https://github.com/narrowspark/automatic/releases"><img src="https://img.shields.io/packagist/v/narrowspark/automatic.svg?style=flat-square"></a>
-    <a href="https://php.net/"><img src="https://img.shields.io/badge/php-%5E7.1.0-8892BF.svg?style=flat-square"></a>
+    <a href="https://php.net/"><img src="https://img.shields.io/badge/php-%5E7.3.0-8892BF.svg?style=flat-square"></a>
     <a href="https://codecov.io/gh/narrowspark/automatic"><img src="https://img.shields.io/codecov/c/github/narrowspark/automatic/master.svg?style=flat-square"></a>
     <a href="#"><img src="https://img.shields.io/badge/style-level%207-brightgreen.svg?style=flat-square&label=phpstan"></a>
     <a href="https://opensource.org/licenses/MIT"><img src="https://img.shields.io/badge/license-MIT-brightgreen.svg?style=flat-square"></a>