govendor: update build instructions and fix #18

vendor/github.com/Sirupsen/logrus/terminal_notwindows.go

@@ -0,0 +1,22 @@
+// 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 linux darwin freebsd openbsd netbsd dragonfly
+// +build !appengine
+
+package logrus
+
+import (
+	"syscall"
+	"unsafe"
+)
+
+// IsTerminal returns true if stderr's file descriptor is a terminal.
+func IsTerminal() bool {
+	fd := syscall.Stderr
+	var termios Termios
+	_, _, err := syscall.Syscall6(syscall.SYS_IOCTL, uintptr(fd), ioctlReadTermios, uintptr(unsafe.Pointer(&termios)), 0, 0, 0)
+	return err == 0
+}