wip #59

	name: Check
	on: [push, pull_request]
	jobs:
	check:
	strategy:
	fail-fast: false
	matrix:
	osFlavor: [ubuntu-20.04, ubuntu-18.04]
	vimFlavor: [neovim, vim]
	vimVersion: [stable, unstable]
	exclude:
	- vimFlavor: vim
	vimVersion: unstable
	runs-on: ${{ matrix.osFlavor }}
	steps:
	- name: Checkout
	uses: actions/checkout@v2
	- name: Enable Universe package repository
	run: \|
	sudo add-apt-repository ${{ matrix.vimVersion == 'stable' && 'universe' \|\| 'ppa:neovim-ppa/unstable' }}
	sudo apt-get update
	- name: Install tmux and ${{ matrix.vimFlavor }}
	run: \|
	sudo apt-get install tmux ${{ matrix.vimFlavor }}
	- name: Review versions
	run: \|
	tmux -V
	${{ matrix.vimFlavor == 'neovim' && 'nvim' \|\| 'vim' }} --version
	# This tests looks for two thigs:
	# * That VIM doesn't hang. If it succedes it will quit quickly. If 5
	# seconds later the tmux session is still running either the runner pane
	# didn't get closed or (more likely) we threw some error and VIM is
	# sitting there expecting us to acknowledge the message(s).
	# * That VIM exited normally. This check isn't very useful since :qa
	# never bubbles up an error, but if someday we use :cq for a test being
	# ready to check the exit code seems like a good thing.
	- name: "Try Vimux"
	run: \|
	ec="$(mktemp)"
	tmux new -s ci -d "${{ matrix.vimFlavor == 'neovim' && 'nvim -u /dev/null --headless' \|\| 'vim' }} -i NONE \"+so plugin/vimux.vim\" \"+VimuxRunCommand('date')\" \"+VimuxCloseRunner \| qa\"; echo \$? > '$ec'"
	sleep 5
	tmux kill-session -t ci && exit 1
	exit "$(cat $ec)"

Provide feedback