All `Macvlan` related test on `DockerSuite` and `DockerNetworkSuite`
are migrated to `macvlan_test.go`.
Also, as `macvlan` seems to be out of experimental, this removes
the *skip* when the run is not experimental (and doesn't start a
daemon with experimental either).
The end goal being to remove the `experimental` builds.
Signed-off-by: Vincent Demeester <vincent@sbr.pm>
Vincent Demeester