Allow PHP 8.0+ and test for it

Author: mdio

.github/workflows/tests.yml

@@ -10,7 +10,7 @@ jobs:
   tests:
     strategy:
       matrix:
-        php-versions: ['7.3', '7.4']
+        php-versions: ['7.3', '7.4', '8.0', '8.1']
 
     runs-on: ubuntu-latest
 

composer.json

@@ -9,7 +9,7 @@
         }
     ],
     "require": {
-        "php": "^7.3",
+        "php": "^7.3|^8.0",
         "symfony/console" : "^2.1|^3.0|^4.0|^5.0",
         "phpunit/php-timer": "^4.0|^5.0"
     },