Change drop_nulls default in `convert()` to false #116

	---
	name: run tests

	on:
	push:
	branches: [main]
	pull_request:
	branches: [main]

	jobs:
	run_tests:
	strategy:
	matrix:
	# matrixed execution for parallel gh-action performance increases
	python_version: ["3.8", "3.9", "3.10"]
	runs-on: ubuntu-latest
	steps:
	- name: Checkout
	uses: actions/checkout@v3
	- name: Python setup
	uses: actions/setup-python@v4
	with:
	python-version: ${{ matrix.python_version }}
	- name: Install poetry
	run: pip install poetry
	- name: Install environment
	run: poetry install --no-interaction --no-ansi
	- name: Run sphinx-docs build test
	run: poetry run sphinx-build docs/source doctest -W
	- name: Run citation file test
	run: poetry run cffconvert --validate
	- name: Run pytest
	run: poetry run pytest

Provide feedback