feat(ldap.dn): Add support for different formats in `ldap.dn2str()` via flags #356

	---
	name: CI

	on: [push, pull_request]

	jobs:
	distros:
	name: "Ubuntu with Python ${{ matrix.python-version }}"
	runs-on: "ubuntu-latest"
	strategy:
	fail-fast: false
	matrix:
	python-version: [3.6, 3.7, 3.8, 3.9, pypy3]
	steps:
	- name: Checkout
	uses: "actions/checkout@v2"
	- name: Install apt dependencies
	run: \|
	set -ex
	sudo apt update
	sudo apt install -y ldap-utils slapd enchant libldap2-dev libsasl2-dev apparmor-utils
	- name: Disable AppArmor
	run: sudo aa-disable /usr/sbin/slapd
	- name: Set up Python ${{ matrix.python-version }}
	uses: actions/setup-python@v2
	with:
	python-version: ${{ matrix.python-version }}
	- name: "Install Python dependencies"
	run: \|
	set -xe
	python -V
	python -m pip install --upgrade pip setuptools
	python -m pip install --upgrade tox tox-gh-actions
	- name: "Test tox with Python ${{ matrix.python-version }}"
	run: "python -m tox"

Provide feedback