Update dockerfile to PHP 8.1 on Alpine 3.18 #99

	name: GrumPHP

	on: [push, pull_request]
	jobs:
	run:
	runs-on: ${{ matrix.operating-system }}
	strategy:
	matrix:
	operating-system: [ubuntu-latest] #windows-latest currently not working
	php-versions: ['8.1'] # , '8.0'
	composer-options: [''] # , '--prefer-lowest' # Don't need this, its not a package
	composer-versions: ['composer:v2'] # , 'composer:v2'
	fail-fast: false
	name: PHP ${{ matrix.php-versions }} @ ${{ matrix.operating-system }} with ${{ matrix.composer-versions }} ${{ matrix.composer-options }}
	steps:
	- name: Checkout
	uses: actions/checkout@master
	- name: Install PHP
	uses: shivammathur/setup-php@master
	with:
	php-version: ${{ matrix.php-versions }}
	tools: ${{ matrix.composer-versions }}
	extensions: xdebug, mbstring, posix
	- name: Check Versions
	run: \|
	php -v
	php -m
	composer --version
	- name: Get composer cache directory
	id: composercache
	run: echo "::set-output name=dir::$(composer config cache-files-dir)"
	- name: Cache dependencies
	uses: actions/cache@v2
	with:
	path: ${{ steps.composercache.outputs.dir }}
	key: ${{ runner.os }}-composer-${{ hashFiles('**/composer.json') }}
	restore-keys: ${{ runner.os }}-composer-
	- name: Install dependencies
	run: composer update --prefer-dist --no-progress --no-suggest ${{ matrix.composer-options }}
	- name: Set git variables
	run: \|
	git config --global user.email "you@example.com"
	git config --global user.name "Your Name"
	- name: Run GrumPHP
	run: php vendor/bin/grumphp run --no-interaction

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