Grenade, for some confusing reason, creates a separate network,
and uses that for upgrade testing as opposed to the original network
the VMs were bound to. If Julia's memory is correct, this was for
multinode upgrade testing.
Anyway, When in UEFI mode, it appears that the TFTP packets
don't get tracked nor cross the boundrary. We likley need to
explicitly address this, but first, lets get the job working as
it was and can then update it.
Also, update requirements because markupsafe removed soft_unicode
method taht was deprecated since a while. Jinja2 started using the
new soft_str method since version 3.0.0
Change-Id: Iaebe966569962b0d3d43774d57b570469479f159
9df7e67e69