Add DefaultAddress to client

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

client_windows.go

@@ -7,6 +7,9 @@ import (
 	winio "github.com/Microsoft/go-winio"
 )
 
+// DefaultAddress is the default unix socket address
+const DefaultAddress = `\\.\pipe\containerd-containerd`
+
 func dialer(address string, timeout time.Duration) (net.Conn, error) {
 	return winio.DialPipe(address, &timeout)
 }