Update README.md #52

	name: Dart CI

	on: [ push, pull_request ]

	jobs:
	test:
	timeout-minutes: 5
	runs-on: ubuntu-latest

	strategy:
	matrix:
	version: [ "2.12", "2.19", "3.0", "beta" ]

	container:
	image: dart:${{ matrix.version }}

	steps:
	- uses: actions/checkout@v2
	- name: Install dependencies
	run: dart pub get
	- name: Run tests
	run: dart pub run test

	test-windows:
	timeout-minutes: 5
	runs-on: windows-latest

	steps:
	- name: Install dart
	run: \|
	choco install dart-sdk
	- uses: actions/checkout@v2
	- name: Install dependencies
	run: C:\tools\dart-sdk\bin\dart.exe pub get
	- name: Run tests
	run: C:\tools\dart-sdk\bin\dart.exe pub run test

	test-macos:
	timeout-minutes: 5
	runs-on: macos-latest

	steps:
	- uses: actions/checkout@v2
	- name: Tap Google's Dart formula repository
	run: brew tap dart-lang/dart
	- name: Install the Dart formula
	run: brew install dart
	- name: Install dependencies
	run: dart pub get
	- name: Run tests
	run: dart pub run test

	format:
	timeout-minutes: 5
	runs-on: ubuntu-latest

	container:
	image: dart:stable

	steps:
	- uses: actions/checkout@v2
	- name: Format
	run: dart format --set-exit-if-changed --fix .

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