Support both
[customizations]
hostname = "whatever"
and
[[customizations]]
hostname = "whatever"
in the blueprint data. The [[ syntax matches the other customization
directives (user, group, sshkey), and as such it's easy to accidentally
use it for the hostname without even realizing it's specifying something
different.
Add some tests for converting customizations to kickstarts.
(cherry picked from commit 35ab6a1336)
bc574e2e2f