Updated python version in workflow #9

	# This workflow will install Python dependencies, lint and execute a mutation testing run using mutmut
	name: Mutation

	on: [pull_request]

	jobs:
	build:

	runs-on: ubuntu-latest

	steps:
	- uses: actions/checkout@v2
	- name: Set up Python 3.9
	uses: actions/setup-python@v2
	with:
	python-version: 3.9
	- name: Install dependencies
	run: \|
	python -m pip install --upgrade pip
	pip install flake8 pytest
	if [ -f requirements.txt ]; then pip install -r requirements.txt; fi
	- name: Lint with flake8
	run: \|
	# stop the build if there are Python syntax errors or undefined names
	flake8 . --count --select=E9,F63,F7,F82 --show-source --statistics
	# exit-zero treats all errors as warnings. The GitHub editor is 127 chars wide
	flake8 . --count --exit-zero --max-complexity=10 --max-line-length=127 --statistics
	- name: Exeucte mutation testing run with mutmut
	continue-on-error: true
	run: \|
	mutmut run --paths-to-mutate app --no-progress
	echo running mutations on code in app folder with mutmut

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