hail-alloc-invalid-network defines a cluster with two nodegroups and an
allocation request which does not fit on any of the groups. Group 1 has
invalid disk-templates while Group 2 is not connected to the right
networks.

hail-alloc-restricted-network defines a cluster wih two nodegroups.
Nodegroup Group 1 is only used as last_resort group, but is chosen by
hail as only this group is connected to the right networks.

Signed-off-by: Thomas Thrainer <thomasth@google.com>
Reviewed-by: Guido Trotter <ultrotter@google.com>