Foreman » Installer

Update Github Actions workflow

This applies the lessons learned while applying this to Voxpupuli and
The Foreman orgs.

Set cron schedule to daily instead of hourly

Switch from Travis CI to Github Actions

Add Github action placeholders

These files need to exist for a Github action to trigger on a PR. The
goal of this commit is to have proper CI checks on the actual PR to
switch over.

[skip ci]