Use PDF to set up the XCI VMs

Use PDF to set up the XCI VMs

This patch is doing the first work item of the spec:

https://github.com/opnfv/releng-xci/blob/master/docs/specs/infra_manager.rst

It creates the required VMs by XCI to afterwards deploy the VIM. It does that
by reading the pdf provided by the user.

- It is currently assumed that the OS for the VM will be installed in the first
disk of the node described by the pdf

- It is assumed that the opnfv VM characteristics are not described in the pdf
but in a similar document called opnfv_vm.yml

- All references to csv from bifrost-create-vm-nodes were removed

Change-Id: I46a85284e4ce7df21cbf66f66619b35f74251e68
Signed-off-by: Manuel Buil <mbuil@suse.com>
Co-Authored-by: Markos Chandras <mchandras@suse.de>