Change to go1.6.1 and vendoring

Godeps/_workspace/src/github.com/kr/pty/run.go

@@ -1,28 +0,0 @@
-package pty
-
-import (
-	"os"
-	"os/exec"
-	"syscall"
-)
-
-// Start assigns a pseudo-terminal tty os.File to c.Stdin, c.Stdout,
-// and c.Stderr, calls c.Start, and returns the File of the tty's
-// corresponding pty.
-func Start(c *exec.Cmd) (pty *os.File, err error) {
-	pty, tty, err := Open()
-	if err != nil {
-		return nil, err
-	}
-	defer tty.Close()
-	c.Stdout = tty
-	c.Stdin = tty
-	c.Stderr = tty
-	c.SysProcAttr = &syscall.SysProcAttr{Setctty: true, Setsid: true}
-	err = c.Start()
-	if err != nil {
-		pty.Close()
-		return nil, err
-	}
-	return pty, err
-}