missing support for unix domain sockets

[hadmut]

It seems as if the gem does not support connecting to REST Servers listening on unix domain (instead on internet TCP) sockets, or at least the documentation doesn't mention it.

E.g. running a sinatra REST server or similar things can and should be run with unix domain socket for security on multi user machines or machines without proper firewall. The Ubuntu snapd makes use of it. Command line client curl supports it. REST over unix domain socket has become a standard.