Migrate network command to cobra

- Migrates network command and subcommands (connect, create, disconnect,
  inspect, list and remove) to spf13/cobra
- Create a RequiredExactArgs helper function for command that require an
  exact number of arguments.

Signed-off-by: Vincent Demeester <vincent@sbr.pm>

cobraadaptor/adaptor.go

@@ -4,6 +4,7 @@ import (
 	"github.com/docker/docker/api/client"
 	"github.com/docker/docker/api/client/container"
 	"github.com/docker/docker/api/client/image"
+	"github.com/docker/docker/api/client/network"
 	"github.com/docker/docker/api/client/volume"
 	"github.com/docker/docker/cli"
 	cliflags "github.com/docker/docker/cli/flags"
@@ -43,6 +44,7 @@ func NewCobraAdaptor(clientFlags *cliflags.ClientFlags) CobraAdaptor {
 		container.NewUnpauseCommand(dockerCli),
 		image.NewRemoveCommand(dockerCli),
 		image.NewSearchCommand(dockerCli),
+		network.NewNetworkCommand(dockerCli),
 		volume.NewVolumeCommand(dockerCli),
 	)
 

usage.go

@@ -23,7 +23,6 @@ var DockerCommandUsage = []Command{
 	{"load", "Load an image from a tar archive or STDIN"},
 	{"login", "Log in to a Docker registry"},
 	{"logout", "Log out from a Docker registry"},
-	{"network", "Manage Docker networks"},
 	{"pause", "Pause all processes within a container"},
 	{"port", "List port mappings or a specific mapping for the CONTAINER"},
 	{"ps", "List containers"},