Rather than setting up and tearing down two identical namespaces,
create it once and use it for the duration of the test. (This is
probably a documentation issue with Infamy: there is no requirement
that test.steps are direct descendants of the test, but until this
point there was no example of this in the source base)
In the process of this, it was also discovered that no positive ping
test was done over v6, so that has been added.
This can now a days be inferred and isn't needed. Also, the interface
type in virtual testing is now etherlike not ethernet.
Signed-off-by: Richard Alpe <richard@bit42.se>