Update vendor directory

Re-added cobra patch 499475bb41

vendor/google.golang.org/appengine/timeout.go

@@ -4,16 +4,13 @@
 
 package appengine
 
-import (
-	"time"
-
-	"github.com/golang/protobuf/proto"
-
-	"google.golang.org/appengine/internal"
-)
+import "golang.org/x/net/context"
 
 // IsTimeoutError reports whether err is a timeout error.
 func IsTimeoutError(err error) bool {
+	if err == context.DeadlineExceeded {
+		return true
+	}
 	if t, ok := err.(interface {
 		IsTimeout() bool
 	}); ok {
@@ -21,29 +18,3 @@ func IsTimeoutError(err error) bool {
 	}
 	return false
 }
-
-// Timeout returns a replacement context that uses d as the default API RPC timeout.
-func Timeout(c Context, d time.Duration) Context {
-	return &timeoutContext{
-		Context: c,
-		d:       d,
-	}
-}
-
-type timeoutContext struct {
-	Context
-	d time.Duration
-}
-
-func (t *timeoutContext) Call(service, method string, in, out proto.Message, opts *internal.CallOptions) error {
-	// Only affect calls that don't have a timeout.
-	if opts == nil || opts.Timeout == 0 {
-		newOpts := new(internal.CallOptions)
-		if opts != nil {
-			*newOpts = *opts
-		}
-		newOpts.Timeout = t.d
-		opts = newOpts
-	}
-	return t.Context.Call(service, method, in, out, opts)
-}