Package manager "dnf" does not work correctly with Salt
(cf https://github.com/saltstack/salt/issues/31001)
It causes Salt to consider that some packages (python, git, curl, etc.) are not
installed, which breaks the Vagrant Kubernetes setup.
Updating dnf and dnf-plugins-core to their latest version solves the issue.
Additionally, I've added the "fastestmirror" to dnf, which is useful if a
RPM mirror is broken or very slow. (In my case, dnf used a broken mirror which
froze the Kubernetes setup).
- wget is not installed by default on fedora 23. Use curl instead
since it is always available on recent Fedora.
- The repo url for cockpit resulted in an http redirect message being
saved as the repo file which broke deployment. Update the url to
url that was redirected to and ensure that future redirects will be
handled correctly.
- The main Fedora 23 repo includes salt packages, and there is no
salt repo for 23. The salt bootstrap still creates a repo file for
a nonexistent repo, though, and this change removes it to avoid
having dnf report an error on every update.
