bump required php version to 7.3

.github/workflows/php.yml

@@ -7,7 +7,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        php-versions: [ '7.3', '7.4', '8.0', '8.1', '8.2', '8.3' ]
+        php-versions: [ '7.3', '8.0', '8.3' ]
 
     steps:
       - uses: actions/checkout@v2

README.md

@@ -30,7 +30,7 @@ echo $router->generate('user-details', ['id' => 5]); // Output: "/users/5"
 
 ## Getting started
 
-You need PHP >= 5.6 to use AltoRouter, although we highly recommend you [use an officially supported PHP version](https://secure.php.net/supported-versions.php) that is not EOL.
+You need PHP >= 7.3 to use AltoRouter, although we highly recommend you [use an officially supported PHP version](https://secure.php.net/supported-versions.php) that is not EOL.
 
 - [Install AltoRouter](https://dannyvankooten.github.io/AltoRouter//usage/install.html)
 - [Rewrite all requests to AltoRouter](https://dannyvankooten.github.io/AltoRouter//usage/rewrite-requests.html)

composer.json

@@ -20,7 +20,7 @@
       }
    ],
    "require": {
-      "php": ">=7.0"
+      "php": ">=7.3"
    },
    "require-dev": {
       "phpunit/phpunit": "9.6.*",