readme: added some ext references #40

	# This workflow will install Python dependencies, run tests and lint with a single version of Python
	# For more information see: https://help.github.com/actions/language-and-framework-guides/using-python-with-github-actions

	name: pymdoccbor

	on:
	push:
	branches: [ "*" ]
	pull_request:
	branches: [ "*" ]

	jobs:
	build:

	runs-on: ubuntu-latest

	strategy:
	fail-fast: false
	matrix:
	python-version:
	- '3.9'
	- '3.10'

	steps:
	- uses: actions/checkout@v2
	- name: Set up Python ${{ matrix.python-version }}
	uses: actions/setup-python@v2
	with:
	python-version: ${{ matrix.python-version }}
	- name: Install system package
	run: \|
	sudo apt update
	sudo apt install python3-dev libssl-dev make automake gcc g++
	- name: Install dependencies
	run: \|
	python -m pip install --upgrade pip
	if [ -f requirements-dev.txt ]; then pip install -r requirements-dev.txt; fi
	if [ -f requirements.txt ]; then pip install -r requirements.txt; fi
	if [ -f requirements-customizations.txt ]; then pip install -r requirements-customizations.txt; fi
	python -m pip install -U setuptools
	python -m pip install -e .
	- name: Lint with flake8
	run: \|
	# stop the build if there are Python syntax errors or undefined names
	flake8 pymdoccbor --count --select=E9,F63,F7,F82 --show-source --statistics
	# exit-zero treats all errors as warnings. The GitHub editor is 127 chars wide
	flake8 pymdoccbor --count --exit-zero --statistics --max-line-length 160
	- name: Tests
	run: \|
	pytest --cov
	- name: Bandit Security Scan
	run: \|
	bandit -r -x pymdoccbor/test* pymdoccbor/*

Provide feedback