Feature removal
We remove support for Python 2
Feature deprecation
``IPIntf`` now supports the same functionalities as ``TCIntf``, so you should use ``IPIntf`` directly
New features
- Add a chain abstraction for iptables
- Add an abstraction for [IPv6 Segment Routing](http://segment-routing.org/)
- Add node names to /etc/hosts (this file is mounted and private to each node)
- Add a new config for routers using both BGP and OSPF/OSPFv3: ``BorderRouterConfig``
- Add the addLinks and addRouters convenience helpers to add multiple links and routers in one line
- Allow DNS zone delegations and DNS root server hints
Main Fixes
- Fix the install of OpenR
Other changes
- Add examples of network with a maximum bandwidth and/or delay
- Document and test ``TopologyDB``
- Add Python type annotations