Add tests badge to README #9

	name: Tests

	on:
	push:
	branches: [master, staging]
	pull_request:
	branches: [master, staging]

	jobs:
	test:
	runs-on: ubuntu-latest

	strategy:
	matrix:
	php: [7.4, 8.0]
	database: [mysql, mariadb, sqlite]
	release: [stable, lowest]
	include:
	- database: sqlite
	pdo: sqlite
	- database: mariadb
	pdo: mysql
	- database: mysql
	pdo: mysql

	services:
	mysql:
	image: mysql:latest
	env:
	MYSQL_ROOT_PASSWORD: password
	MYSQL_DATABASE: test
	ports:
	- 3306
	mariadb:
	image: mariadb:latest
	env:
	MYSQL_ROOT_PASSWORD: password
	MYSQL_DATABASE: test
	ports:
	- 3306

	steps:
	- uses: actions/checkout@v3
	with:
	fetch-depth: 2
	- uses: actions/cache@v3
	with:
	path: ~/.cache/composer/files
	key: php-${{ matrix.php }}-composer-${{ hashFiles('**/composer.lock') }}
	- uses: shivammathur/setup-php@v2
	with:
	php-version: ${{ matrix.php }}
	coverage: none
	tools: pecl
	extensions: bcmath, ctype, json, mbstring, openssl, pdo, pdo_${{ matrix.pdo }}, tokenizer, xml
	- run: composer update --no-interaction --no-progress --prefer-dist --prefer-${{ matrix.release }}
	- run: \|
	composer test
	env:
	DATABASE: ${{ matrix.database }}
	MYSQL_PORT: ${{ job.services.mysql.ports[3306] }}
	MARIADB_PORT: ${{ job.services.mariadb.ports[3306] }}

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