keep null values in to_singer if catalog_schema #114

	### A CI workflow template that runs linting and python testing

	name: Test gluestick

	on: [push]

	jobs:
	linting:

	runs-on: ubuntu-latest
	strategy:
	matrix:
	# Only lint using the primary version used for dev
	python-version: [3.7]

	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 dependencies
	run: \|
	pip install .
	pip install tox
	- name: Run lint command from tox.ini
	run: \|
	tox -e lint

	pytest:

	runs-on: ubuntu-latest
	env:
	GITHUB_TOKEN: ${{secrets.GITHUB_TOKEN}}
	strategy:
	matrix:
	python-version: [3.7, 3.8, 3.9]

	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 dependencies
	run: \|
	pip install .
	pip install pytest
	- name: Test with pytest
	run: \|
	pytest --capture=no

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