Imports of networkdb-test command

PathSynopsis
github.com/docker/docker/libnetwork/cmd/networkdb-test/dbclient
github.com/docker/docker/libnetwork/cmd/networkdb-test/dbserver
github.com/sirupsen/logrusPackage logrus is a structured logger for Go, completely API compatible with the standard library logger.
logPackage log implements a simple logging package.
osPackage os provides a platform-independent interface to operating system functionality.