Switch to kingpin flags (#639)

* Switch to kingpin flags

* Fix logrus vendoring

* Fix flags in main tests

* Fix vendoring versions

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

@@ -0,0 +1,28 @@
+// 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 (
+	"io"
+	"os"
+	"syscall"
+	"unsafe"
+)
+
+// IsTerminal returns true if stderr's file descriptor is a terminal.
+func IsTerminal(f io.Writer) bool {
+	var termios Termios
+	switch v := f.(type) {
+	case *os.File:
+		_, _, err := syscall.Syscall6(syscall.SYS_IOCTL, uintptr(v.Fd()), ioctlReadTermios, uintptr(unsafe.Pointer(&termios)), 0, 0, 0)
+		return err == 0
+	default:
+		return false
+	}
+}