IPv6 support

[lvlts]

Currently, IPv6 is not supported in the Travis environment. More information is available at:
https://docs.travis-ci.com/user/reference/overview/#Virtualisation-Environment-vs-Operating-System

Further exploration can be done in the following directions (or others):

• 4to6 tunnel on Travis CI: not sure if it can be done without port forwarding, at least not with native iproute2 tooling; reliability is also questionable, depending on the 4to6 provider.
• migration of the current project to another "test" build environment where native IPv6 is present; regular deployment to github pages can be done regularly via cron or other means.

[Mikaela]

Crazy idea, could this be done using Teredo or does it require something Travic CI doesn't provide? I think it would be matter of installing miredo or at least is on normal machines.

Alternatively probably not much less crazy idea could it attempt using Tor proxy within hype that has in its torrc something like SocksPort [fc...]:1234 NoIPv4Traffic ?

[lvlts]

Crazy idea, could this be done using Teredo or does it require something Travic CI doesn't provide? I think it would be matter of installing miredo or at least is on normal machines.

Awesome idea, I've just had a go at it, but it seems that the miredo interface just won't get assigned an IP address. I have the strong feeling that this is because IPv6 is only available on loopback for trusty containers. For non-container trusty, IPv6 is not available at all, which might be the reason why it's also not showing up.

Alternatively probably not much less crazy idea could it attempt using Tor proxy within hype that has in its torrc something like SocksPort [fc...]:1234 NoIPv4Traffic ?

This one's even tougher to implement, and I'm afraid the result would be similar, as there's no IPv6 support enabled on the other interfaces.

Definitely something to test out for the future.