chore: upgrade supported language versions

Author: Sam Harrison

.github/workflows/test-and-deploy.yml

@@ -17,7 +17,7 @@ jobs:
     timeout-minutes: 20
     strategy:
       matrix:
-        php: [ 5.6, 7.0, 7.1, 7.2, 7.3, 7.4 ]
+        php: [ '5.6', '7.0', '7.1', '7.2', '7.3', '7.4', '8.0', '8.1' ]
         dependencies:
           - "lowest"
           - "highest"
@@ -56,7 +56,7 @@ jobs:
       - name: Setup PHP
         uses: shivammathur/[email protected]
         with:
-          php-version: '7.4'
+          php-version: '8.1'
         id: php
 
       - name: Build Release Artifacts

README.md

@@ -29,7 +29,7 @@ All updates to this library are documented in our [CHANGELOG](CHANGELOG.md).
 
 ## Prerequisites
 
-- PHP version 5.6, 7.0, 7.1, 7.2, 7.3, or 7.4
+- PHP version 5.6, 7.0, 7.1, 7.2, 7.3, 7.4, 8.0, or 8.1
 
 ## Install with Composer