Resolve "Use kypo-topology-definition 0.5.0"

• A version compatible with kypo-topology-definition 0.5.0 (~=0.5.0) is now required.
• The topology definition attributes have been updated according to this version.
• It is no longer possible to create sandboxes with a border router.
• All routers are part of a network defined in the wan clause of the topology definition, and they access other local networks using this network.
• All hosts access the Internet through a router.
• Creating a topology without a router (a single host) is still possible. In this case, the host can directly access the Internet. This topology is not compatible with kypo.

Closes #95 (closed)