Support torchrun+SLURM multi-node trainings in `ReturnnTrainingJob` #1347

	name: job_tests
	on:
	push:
	branches:
	- main
	pull_request:
	branches:
	- main
	jobs:
	test-jobs:
	runs-on: ubuntu-latest
	steps:
	- uses: actions/checkout@v2
	with:
	repository: "rwth-i6/i6_core"
	path: "i6_core"
	- uses: actions/checkout@v2
	with:
	repository: "rwth-i6/sisyphus"
	path: "sisyphus"
	- uses: actions/checkout@v2
	with:
	repository: "rwth-i6/returnn"
	path: "returnn"
	- uses: actions/setup-python@v2
	with:
	python-version: 3.8
	cache: 'pip'
	- name: Setup Sisyphus environment
	run: \|
	pip install --user --upgrade pip setuptools wheel
	cd sisyphus
	pip install .
	cd ..
	pip install pytest
	sudo apt update && sudo apt install -y libsndfile1
	pip install -r i6_core/requirements.txt
	pip install -r returnn/requirements.txt
	- name: Test Jobs
	run: \|
	set -e
	pytest i6_core/tests/job_tests

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