Do not create default user, only root account (with password 'root').

Signed-off-by: Ville Korhonen <ville@xd.fi>
Allow root access via SSH.
Revert "Allow root access via SSH."

This reverts commit b240c2eafffd352aafe850bd2d4850f24828089b.
Revert "Do not create default user, only root account (with password 'root')."

This reverts commit 8b9f8b17fe806ea48150e1bbd1f41051a1a80fc9.
Remove vagrant user creation.