Restructure the Dockerfile and use Ansible for provisioning
Restructure the Dockerfile and use Ansible for provisioning

ENV instructions: In Docker 1.10 and higher, ENV instructions does not
create layers. Furthermore when using multiline ENV instructions the
variables cannot reference the ones defined earlier. Therefore the ENV
instructions were kept sparately.

VOLUME instruction: has to be after ENV because it references variable
from ENV instruction.

RUN instructions:
 - password update has to be after the passwd is installed
 - dnf installation arguments were split to multiline and sorted to
   avoid duplication and to ease the processes of updates and PR
   reviews
 - sudo and libvirt packages are not used anymore so not installed

CMD instruction:
 - Ansible playbook is used for provisioning
 - since libvirt is not used any more, mknod is not needed

vinzenz/prototype,leapp-to/prototype,leapp-to/prototype,leapp-to/prototype,vinzenz/prototype,vinzenz/prototype,leapp-to/prototype,vinzenz/prototype