Separate out pre and post user snippets. #335

	name: Basic CI
	on: [push, pull_request]

	jobs:
	basic_ci:
	name: Basic CI
	runs-on: ubuntu-22.04
	strategy:
	matrix:
	python-version: [3.8, '3.10']
	steps:
	- uses: actions/checkout@v3
	- name: Set up Python ${{ matrix.python-version }}
	uses: actions/setup-python@v4
	with:
	python-version: ${{ matrix.python-version }}
	- name: Install Dependencies And Self
	run: \|
	python -m pip install --upgrade pip setuptools wheel
	python -m pip install -e .[test] codecov pytest-cov
	- name: Run headless tests
	uses: coactions/setup-xvfb@v1
	with:
	run: python -m pytest -s -v --cov=rocker -m "not nvidia"
	- name: Upload coverage to Codecov
	uses: codecov/codecov-action@v3

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