Fix legacy HHVM build by downgrading Composer

Author: SimonFrings

.github/workflows/ci.yml

@@ -58,6 +58,7 @@ jobs:
       - uses: azjezz/setup-hhvm@v1
         with:
           version: lts-3.30
+      - run: composer self-update --2.2 # downgrade Composer for HHVM
       - run: hhvm $(which composer) install
       - run: hhvm vendor/bin/phpunit
       - run: time php examples/91-benchmark-throughput.php

README.md

@@ -1,6 +1,6 @@
 # Stream
 
-[![CI status](https://github.com/reactphp/stream/workflows/CI/badge.svg)](https://github.com/reactphp/stream/actions)
+[![CI status](https://github.com/reactphp/stream/actions/workflows/ci.yml/badge.svg)](https://github.com/reactphp/stream/actions)
 [![installs on Packagist](https://img.shields.io/packagist/dt/react/stream?color=blue&label=installs%20on%20Packagist)](https://packagist.org/packages/react/stream)
 
 Event-driven readable and writable streams for non-blocking I/O in [ReactPHP](https://reactphp.org/).