Test `slope` of non-vertical `axline` #215

	name: Tests

	on:
	push:
	branches:
	- '*'

	jobs:
	test:

	runs-on: ubuntu-20.04
	strategy:
	matrix:
	python-version: ["3.9"]
	matplotlib-version: [3.4.0, 3.5.0, 3.6.0, 3.7.0, 3.8.0]

	steps:
	- uses: actions/checkout@v4
	- name: Set up Python ${{ matrix.python-version }}
	uses: actions/setup-python@v5
	with:
	python-version: ${{ matrix.python-version }}

	- name: Install OS dependencies
	run: \|
	sudo apt-get update -yy
	sudo apt-get install -yy \
	inkscape
	- name: Install Python dependencies
	run: \|
	python -m pip install --upgrade pip

	python -m pip install numpy==1.26.4
	python -m pip install pillow==9.0
	python -m pip install matplotlib==${{ matrix.matplotlib-version }}
	python -m pip install pytest>=4.6
	python -m pip install pytest-cov
	python -m pip install codecov coverage
	- name: Run pytest
	run: \|
	python -mpytest -ra \
	--cov=./ --log-level=DEBUG --color=yes
	- name: Upload code coverage
	uses: codecov/codecov-action@v4
	with:
	token: ${{ secrets.CODECOV_TOKEN }}

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