1. terraform files for deploying two paloAlto Firewalls in a HA Setup
 - important thing is to enable port_security on the interfaces which will hold the vip
 - the interface with the VIP must not be attached to a server!
 - also the internal VIP IP has to be added as allowed_address, otherwise the move of the floating IP will not work.
   It is not possible to a CIDR here. The IP must be set with /32.
 - if you enable port_security also a security rule must be added with the relevant rules.
 - the interfaces are added to the same network on firewall 1 and 2 for HA.