php: Drop PHP 5.6 support

.github/workflows/php.yml

@@ -17,13 +17,8 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        php: ['5.6', '7.0', '7.1', '7.2', '7.3', '7.4', '8.0']
+        php: ['7.0', '7.1', '7.2', '7.3', '7.4', '8.0', '8.1']
         os: ['ubuntu-latest']
-        include:
-          - php: '5.6'
-            allow_failure: true
-          - php: '7.0'
-            allow_failure: true
 
     steps:
       - name: Checkout code base
@@ -51,20 +46,18 @@ jobs:
     runs-on: ${{ matrix.os }}
 
     env:
-      phpunit-version: 8.5.15
+      phpunit-version: 8.5
 
     strategy:
       fail-fast: false
       matrix:
-        php: ['5.6', '7.0', '7.1', '7.2', '7.3', '7.4', '8.0']
+        php: ['7.0', '7.1', '7.2', '7.3', '7.4', '8.0', '8.1']
         os: ['ubuntu-latest']
         include:
-          - php: '5.6'
-            phpunit-version: 5.7.27
           - php: '7.0'
-            phpunit-version: 6.5.14
+            phpunit-version: 6.5
           - php: '7.1'
-            phpunit-version: 7.5.20
+            phpunit-version: 7.5
 
     steps:
       - name: Checkout code base

README.md

@@ -1,6 +1,6 @@
 # Icinga PHP Library - Standard Library
 
-[![PHP Support](https://img.shields.io/badge/php-%3E%3D%205.6-777BB4?logo=PHP)](https://php.net/)
+[![PHP Support](https://img.shields.io/badge/php-%3E%3D%207.0-777BB4?logo=PHP)](https://php.net/)
 ![Build Status](https://github.com/Icinga/ipl-stdlib/workflows/PHP%20Tests/badge.svg?branch=master)
 
 This is the Stdlib prototype for the Icinga PHP library ([ipl](https://github.com/Icinga/ipl)).

composer.json

@@ -4,7 +4,7 @@
     "type": "library",
     "license": "MIT",
     "autoload": {
-        "files": ["src/functions_include.php", "src/polyfill-php71.php", "src/polyfill-php70.php"],
+        "files": ["src/functions_include.php", "src/polyfill-php71.php"],
         "psr-4": {
             "ipl\\Stdlib\\": "src"
         }
@@ -15,7 +15,7 @@
         }
     },
     "require": {
-        "php": ">=5.6.0",
+        "php": ">=7.0",
         "ext-openssl": "*",
         "evenement/evenement": "^2"
     }