Refactor network and veth creation

Remove veth interfaces on the host if an error occurs.
Provide the host interface name, temporary peer interface name and the
name of the peer once it is inside the container's namespace in the
Network config.

Signed-off-by: Michael Crosby <crosbymichael@gmail.com>

linux_standard_init.go

@@ -35,7 +35,7 @@ func (l *linuxStandardInit) Init() error {
 			return err
 		}
 	}
-	if err := setupNetwork(l.config.Config); err != nil {
+	if err := setupNetwork(l.config); err != nil {
 		return err
 	}
 	if err := setupRoute(l.config.Config); err != nil {