Adding IPv6 network support

Docker-DCO-1.1-Signed-off-by: Malte Janduda <mail@janduda.net> (github: MalteJ)
Address6 -> IPv6Address and Gateway6 -> IPv6Gateway

Docker-DCO-1.1-Signed-off-by: Malte Janduda <mail@janduda.net> (github: MalteJ)
Merge pull request #203 from MalteJ/master

Adding IPv6 network support