Keep up-to-date with a list of git repos using vis.

Given a set of git repos, we fetch commit hashes using git ls-remote and store them on disk.

We then compare the local cache with the latest hashes to see if they are up-to-date.

outdated - compare local hashes to latest

outdated-update - write latest hashes to file

Just set repos to an array of git repositories

require('plugins/vis-outdated').repos = {
	'https://github.com/erf/vis-title',
	'https://github.com/erf/vis-cursors',
	'https://github.com/erf/vis-highlight',
}

github urls can be shortend to only {name}/{repo}

require('plugins/vis-outdated').repos = {
	'erf/vis-title',
	'erf/vis-cursors',
	'erf/vis-highlight',
}

repos and commits are cached in {XDG_CACHE_HOME|HOME}.vis-outdated.csv.