Enable php 7.2-8.1 builds via GitHub CI

.gitattributes

@@ -1,7 +1,7 @@
 .coveralls.yml export-ignore
 .gitattributes export-ignore
+.github/ export-ignore
 .gitignore export-ignore
-.travis.yml export-ignore
 composer.json export-ignore
 phpunit.xml.dist export-ignore
 tests export-ignore

.github/workflows/CI.yaml

@@ -0,0 +1,40 @@
+name: CI
+on:
+  - push
+  - pull_request
+
+# A workflow run is made up of one or more jobs that can run sequentially or in parallel
+jobs:
+
+  php:
+    strategy:
+      matrix:
+        include:
+          # Has php7.2-8.1 and composer 2 pre-installed
+          # https://github.com/actions/virtual-environments/blob/ubuntu18/20220626.1/images/linux/Ubuntu1804-Readme.md#php
+          - os: ubuntu-18.04
+            php: "7.2"
+          - os: ubuntu-18.04
+            php: "7.3"
+          # Has php7.4-8.1 and composer 2 pre-installed
+          # https://github.com/actions/virtual-environments/blob/ubuntu20/20220626.1/images/linux/Ubuntu2004-Readme.md#php
+          - os: ubuntu-20.04
+            php: "7.4"
+          - os: ubuntu-20.04
+            php: "8.0"
+          - os: ubuntu-20.04
+            php: "8.1"
+    # Use "PHP 0.0" as job name instead of "php (ubuntu-, 0.0)"
+    name: PHP ${{ matrix.php }}
+    runs-on: ${{ matrix.os }}
+    steps:
+      - uses: actions/checkout@v2
+
+      - name: Use PHP ${{ matrix.php }}
+        run: sudo update-alternatives --set php /usr/bin/php${{ matrix.php }}
+
+      - name: composer install
+        run: composer install
+
+      - name: composer test
+        run: composer test

README.md

@@ -1,6 +1,8 @@
+[![CI Status](https://github.com/pleonasm/bloom-filter/actions/workflows/CI.yaml/badge.svg)](https://github.com/pleonasm/bloom-filter/actions/workflows/CI.yaml)
+
 # A Bloom Filter for PHP #
 
-This is a well tested implementation of a [Bloom Filter](http://en.wikipedia.org/wiki/Bloom_filter)
+This is a well tested implementation of a [Bloom Filter](https://en.wikipedia.org/wiki/Bloom_filter)
 for PHP. It has the following features:
 
 1. Efficient memory use for bit array (as efficient as PHP can be anyway).
@@ -17,7 +19,7 @@ your path or in your project).
 
 Put the following in your package.json:
 
-```javascript
+```json
 {
     "require": {
         "pleonasm/bloom-filter": "*"

composer.json

@@ -20,6 +20,9 @@
         "phpunit/phpunit": "^6.5 || ^7.5 || ^8.5 || ^9.4",
         "php-coveralls/php-coveralls": "^2.0"
     },
+    "scripts": {
+        "test": "phpunit"
+    },
     "autoload": {
         "psr-4": { "Pleo\\BloomFilter\\": "src/" }
     }