Convert kickstart userdata to cloud-config, and take ssh-keys as params

Will require https://github.com/theforeman/foreman/pull/1586
I think this should work be the same as fix-hosts:

    [cloud-user@ostest99 ~]$ cat /etc/hosts
    # Your system has configured 'manage_etc_hosts' as True.
    # As a result, if you wish for changes to this file to persist
    # then you will need to either
    # a.) make changes to the master file in /etc/cloud/templates/hosts.redhat.tmpl
    # b.) change or remove the value of 'manage_etc_hosts' in
    #     /etc/cloud/cloud.cfg or cloud-config from user-data
    # The following lines are desirable for IPv4 capable hosts
    127.0.0.1 ostest99.novalocal ostest99 
    127.0.0.1 localhost.localdomain localhost
    127.0.0.1 localhost4.localdomain4 localhost4

    # The following lines are desirable for IPv6 capable hosts
    ::1 ostest99.novalocal ostest99
    ::1 localhost.localdomain localhost
    ::1 localhost6.localdomain6 localhost6

    [cloud-user@ostest99 ~]$ hostname
    ostest99
    [cloud-user@ostest99 ~]$ hostname -f
    ostest99.novalocal
    [cloud-user@ostest99 ~]$ hostname -s
    ostest99