Make this utility a helper, so that the "skip" message is printing
the location of the test, instead of the location of the helper,
which is what it's printing now:
requirement.go:26: unmatched requirement bridgeNfIptables
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
split all non-cli portions into a new internal/test/environment package
Set a test environment on packages instead of creating new ones.
Signed-off-by: Daniel Nephin <dnephin@docker.com>
