vendor: sirupsen/logrus -> Sirupsen/logrus

github.com/docker/docker/pkg/archive requires Sirupsen/logrus.
So let's remove sirupsen/logrus at the moment.

Signed-off-by: Akihiro Suda <suda.akihiro@lab.ntt.co.jp>

vendor/github.com/sirupsen/logrus/terminal_windows.go

@@ -1,27 +0,0 @@
-// Based on ssh/terminal:
-// Copyright 2011 The Go Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style
-// license that can be found in the LICENSE file.
-
-// +build windows,!appengine
-
-package logrus
-
-import (
-	"syscall"
-	"unsafe"
-)
-
-var kernel32 = syscall.NewLazyDLL("kernel32.dll")
-
-var (
-	procGetConsoleMode = kernel32.NewProc("GetConsoleMode")
-)
-
-// IsTerminal returns true if stderr's file descriptor is a terminal.
-func IsTerminal() bool {
-	fd := syscall.Stderr
-	var st uint32
-	r, _, e := syscall.Syscall(procGetConsoleMode.Addr(), 2, uintptr(fd), uintptr(unsafe.Pointer(&st)), 0)
-	return r != 0 && e == 0
-}