Comment 3 for bug 797419

I think the easiest and possibly most correct thing to do is put routes 1.12 as a requirement.
I've noticed errors even in Openstack API when routes 1.10 is employed; therefore there's little point in tweaking the code so that it works with routes 1.10 as well.

I'm going to add Routes>=1.12 in pip-requires, unless we agree on a different strategy.