Change to go1.6.1 and vendoring

vendor/github.com/kr/pty/README.md

@@ -0,0 +1,36 @@
+# pty
+
+Pty is a Go package for using unix pseudo-terminals.
+
+## Install
+
+    go get github.com/kr/pty
+
+## Example
+
+```go
+package main
+
+import (
+	"github.com/kr/pty"
+	"io"
+	"os"
+	"os/exec"
+)
+
+func main() {
+	c := exec.Command("grep", "--color=auto", "bar")
+	f, err := pty.Start(c)
+	if err != nil {
+		panic(err)
+	}
+
+	go func() {
+		f.Write([]byte("foo\n"))
+		f.Write([]byte("bar\n"))
+		f.Write([]byte("baz\n"))
+		f.Write([]byte{4}) // EOT
+	}()
+	io.Copy(os.Stdout, f)
+}
+```