Use Socket.ip_address_list to get loopback addresses #1318
This will fix #1167
Need some guidance from @evanphx here: is binder supposed to bind to only loopback interfaces by default (as I've done in this PR) or is it supposed to bind to linklocal addresses as well?
Here's what this method returned before (my machine, CRuby):
Note the omission of an ipv6 link-local interface. The reason I removed it was that there are several other link-local interfaces on my machine which I don't think puma should bind to:
@evanphx if you can clarify the intent here, I'll add a test.