use pypi.io url instead of api, support update checksum for pypi, add doc #356

	name: CI checks

	on:
	push:
	branches: [ staging, production, dx ]
	pull_request:
	branches: [ staging, production ]

	jobs:
	build:

	runs-on: ubuntu-latest

	steps:
	- uses: actions/checkout@v2
	- name: Set up Python 3.8
	uses: actions/setup-python@v2
	with:
	python-version: 3.8
	- name: Install dependencies
	run: \|
	python -m pip install --upgrade pip
	pip install flake8 mypy pyparsing
	if [ -f requirements.txt ]; then pip install -r requirements.txt; fi
	- name: Type checking using mypy
	run: \|
	mypy -p acbs
	- name: Lint with flake8
	run: \|
	# stop the build if there are Python syntax errors or undefined names
	flake8 . --exclude='build,.mypy_cache,venv,dist' --count --select=E9,F63,F7,F82 --show-source --statistics
	# exit-zero treats all errors as warnings. The GitHub editor is 127 chars wide
	flake8 . --exclude='build,.mypy_cache,venv,dist' --count --exit-zero --max-complexity=10 --max-line-length=127 --statistics
	- name: Run unittests
	run: ARCH=amd64 python -m unittest discover ./tests/
	- name: Install native dependencies
	run: sudo apt-get update && sudo apt-get install -y libapt-pkg-dev
	- name: Test building
	run: python setup.py build -f

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