Ubuntu fixes

[matt22207]

Fixes for Ubuntu:

• Updated kernel-param-utils since Ubuntu uses update-grub, not grub2-mkconfig
• Change docker to install via snap. The docker in the apt repository is not really docker:

$ apt info docker

Package: docker
Version: 1.5-2
Priority: optional
Section: universe/x11
Origin: Ubuntu
Maintainer: Ubuntu Developers <ubuntu-devel-discuss@lists.ubuntu.com>
Original-Maintainer: Paul Tagliamonte <paultag@debian.org>
Bugs: https://bugs.launchpad.net/ubuntu/+filebug
Installed-Size: 9,216 B
Depends: wmdocker
Download-Size: 1,316 B
APT-Manual-Installed: yes
APT-Sources: http://us.archive.ubuntu.com/ubuntu hirsute/universe amd64 Packages
Description: transitional package
 This is a transitional package for system tray docking application.
 It can safely be removed.

The docker snap package is maintained by Canonical: https://snapcraft.io/docker