Use a more modern interface theme when using Linux. #100

	# This workflow checks that the unit tests still run OK

	name: Unit Test Check
	on:
	push:
	pull_request:

	jobs:
	unit_tests:
	name: unit_tests
	runs-on: ubuntu-latest
	steps:
	- uses: actions/checkout@v3
	- name: check tests run
	run: \|
	python3 test_all.py

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