vendorize: update all vendorized packages. (#2206)

Bring in new changes from upstream for all the packages.

Important ones include
   - gorilla/mux
   - logrus
   - jwt

vendor/github.com/rs/xhandler/xhandler.go

@@ -0,0 +1,42 @@
+// Package xhandler provides a bridge between http.Handler and net/context.
+//
+// xhandler enforces net/context in your handlers without sacrificing
+// compatibility with existing http.Handlers nor imposing a specific router.
+//
+// Thanks to net/context deadline management, xhandler is able to enforce
+// a per request deadline and will cancel the context in when the client close
+// the connection unexpectedly.
+//
+// You may create net/context aware middlewares pretty much the same way as
+// you would with http.Handler.
+package xhandler // import "github.com/rs/xhandler"
+
+import (
+	"net/http"
+
+	"golang.org/x/net/context"
+)
+
+// HandlerC is a net/context aware http.Handler
+type HandlerC interface {
+	ServeHTTPC(context.Context, http.ResponseWriter, *http.Request)
+}
+
+// HandlerFuncC type is an adapter to allow the use of ordinary functions
+// as an xhandler.Handler. If f is a function with the appropriate signature,
+// xhandler.HandlerFuncC(f) is a xhandler.Handler object that calls f.
+type HandlerFuncC func(context.Context, http.ResponseWriter, *http.Request)
+
+// ServeHTTPC calls f(ctx, w, r).
+func (f HandlerFuncC) ServeHTTPC(ctx context.Context, w http.ResponseWriter, r *http.Request) {
+	f(ctx, w, r)
+}
+
+// New creates a conventional http.Handler injecting the provided root
+// context to sub handlers. This handler is used as a bridge between conventional
+// http.Handler and context aware handlers.
+func New(ctx context.Context, h HandlerC) http.Handler {
+	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		h.ServeHTTPC(ctx, w, r)
+	})
+}