Ansible facts aren't always enough to determine if a distro is derived
from Ubuntu or not, this is available from `/etc/os-release` when it
contains `ID_LIKE="ubuntu debian"`. This patch uses `/etc/os-release` to
correctly handle Ubuntu installations, e.g. PPA's, for all Ubuntu
derived dirtros rather than just Ubuntu itself.
Fixes#16 by replacing uses of the `apt_key:` module with `get_url:` to
download apt keyrings into `/etc/apt/keyrings`, then used
`signed-by=/etc/path/keyrings/<keyring>` in the appropriate sources.list
file.
