Support PHP 8

Author: SimonFrings

.github/workflows/ci.yml

@@ -11,6 +11,7 @@ jobs:
     strategy:
       matrix:
         php:
+          - 8.0
           - 7.4
           - 7.3
           - 7.2

README.md

@@ -641,7 +641,7 @@ $ composer require clue/stdio-react:^2.4
 See also the [CHANGELOG](CHANGELOG.md) for details about version upgrades.
 
 This project aims to run on any platform and thus does not require any PHP
-extensions and supports running on legacy PHP 5.3 through current PHP 7+ and
+extensions and supports running on legacy PHP 5.3 through current PHP 8+ and
 HHVM.
 It's *highly recommended to use PHP 7+* for this project.