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/gorilla/handlers/cors.go

@@ -112,6 +112,9 @@ func (ch *cors) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 
 	w.Header().Set(corsAllowOriginHeader, origin)
 
+	if r.Method == corsOptionMethod {
+		return
+	}
 	ch.h.ServeHTTP(w, r)
 }