If we leave the root account w/o a password people will use it that way,
leading to insecure images. Also if we use a default password. So lock
the root account in the templates.
Users will need to do one of these things:
1. Use [[customizations.user]] in their blueprint to configure root or
another user.
2. Use [[customizations.sshkey]] to set a key for root
2. Install a package that configures a user at install time
3. Install a package that sets up a user at boot time (eg. cloud-init)
This also drops the auth line from the kickstart templates, allowing it
to use the default password algoritm instead of md5.
Resolves: rhbz#1626122
Currently we are making MBR disk images for qcow2 and partitioned disk,
so the UEFI packages aren't required at this point.
Move the clearpart command into compose.py so that in the futute it can
use clearpart --disklabel to create a GPT image, and add the required
packages to the package set.
