Code review comment for ~raphael-glon/cloud-init:master

I've taken a look and I can confirm that for v6 routes, route needs the network with prefix.
This is information is present in the internal network_state of the route so a little juggling is needed to always use network/prefix when rendering route and ensure that on v6 routes we use -A inet6.

I've added the test-case from the bug and a few others.

This passes tox and does not regress anything.

Please consider applying this instead

http://paste.ubuntu.com/p/s3tYjGv3Jh/