Update sphinx requirement from <3 to <8 #27

	name: CI
	on:
	push:
	branches: master
	pull_request:
	jobs:
	test:
	runs-on: ubuntu-latest
	name: test (Python ${{ matrix.python-version }})
	strategy:
	matrix:
	python-version: [3.6, 3.7, 3.8, 3.9]
	steps:
	- uses: actions/checkout@v2
	- name: Set up Python
	uses: actions/setup-python@v2
	with:
	python-version: "${{ matrix.python-version }}"
	- name: Install tox
	run: \|
	python -m pip install --upgrade pip
	pip install tox tox-gh-actions
	- name: Run tests
	run: tox
	- name: Upload coverage to Codecov
	uses: codecov/codecov-action@v1

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