Update vendoring via vndr

gateway/vendor/github.com/gorilla/mux/README.md

@@ -15,7 +15,7 @@ The name mux stands for "HTTP request multiplexer". Like the standard `http.Serv
 
 * It implements the `http.Handler` interface so it is compatible with the standard `http.ServeMux`.
 * Requests can be matched based on URL host, path, path prefix, schemes, header and query values, HTTP methods or using custom matchers.
-* URL hosts and paths can have variables with an optional regular expression.
+* URL hosts, paths and query values can have variables with an optional regular expression.
 * Registered URLs can be built, or "reversed", which helps maintaining references to resources.
 * Routes can be used as subrouters: nested routes are only tested if the parent route matches. This is useful to define groups of routes that share common conditions like a host, a path prefix or other repeated attributes. As a bonus, this optimizes request matching.
 
@@ -24,9 +24,9 @@ The name mux stands for "HTTP request multiplexer". Like the standard `http.Serv
 * [Install](#install)
 * [Examples](#examples)
 * [Matching Routes](#matching-routes)
-* [Listing Routes](#listing-routes)
 * [Static Files](#static-files)
 * [Registered URLs](#registered-urls)
+* [Walking Routes](#walking-routes)
 * [Full Example](#full-example)
 
 ---
@@ -168,7 +168,6 @@ s.HandleFunc("/{key}/", ProductHandler)
 // "/products/{key}/details"
 s.HandleFunc("/{key}/details", ProductDetailsHandler)
 ```
-
 ### Listing Routes
 
 Routes on a mux can be listed using the Router.Walk method—useful for generating documentation:
@@ -179,6 +178,7 @@ package main
 import (
     "fmt"
     "net/http"
+    "strings"
 
     "github.com/gorilla/mux"
 )
@@ -190,15 +190,25 @@ func handler(w http.ResponseWriter, r *http.Request) {
 func main() {
     r := mux.NewRouter()
     r.HandleFunc("/", handler)
-    r.HandleFunc("/products", handler)
-    r.HandleFunc("/articles", handler)
-    r.HandleFunc("/articles/{id}", handler)
+    r.HandleFunc("/products", handler).Methods("POST")
+    r.HandleFunc("/articles", handler).Methods("GET")
+    r.HandleFunc("/articles/{id}", handler).Methods("GET", "PUT")
     r.Walk(func(route *mux.Route, router *mux.Router, ancestors []*mux.Route) error {
         t, err := route.GetPathTemplate()
         if err != nil {
             return err
         }
-        fmt.Println(t)
+        // p will contain regular expression is compatible with regular expression in Perl, Python, and other languages.
+        // for instance the regular expression for path '/articles/{id}' will be '^/articles/(?P<v0>[^/]+)$'
+        p, err := route.GetPathRegexp()
+        if err != nil {
+            return err
+        }
+        m, err := route.GetMethods()
+        if err != nil {
+            return err
+        }
+        fmt.Println(strings.Join(m, ","), t, p)
         return nil
     })
     http.Handle("/", r)
@@ -258,19 +268,21 @@ url, err := r.Get("article").URL("category", "technology", "id", "42")
 "/articles/technology/42"
 ```
 
-This also works for host variables:
+This also works for host and query value variables:
 
 ```go
 r := mux.NewRouter()
 r.Host("{subdomain}.domain.com").
   Path("/articles/{category}/{id:[0-9]+}").
+  Queries("filter", "{filter}")
   HandlerFunc(ArticleHandler).
   Name("article")
 
-// url.String() will be "http://news.domain.com/articles/technology/42"
+// url.String() will be "http://news.domain.com/articles/technology/42?filter=gorilla"
 url, err := r.Get("article").URL("subdomain", "news",
                                  "category", "technology",
-                                 "id", "42")
+                                 "id", "42",
+                                 "filter", "gorilla")
 ```
 
 All variables defined in the route are required, and their values must conform to the corresponding patterns. These requirements guarantee that a generated URL will always match a registered route -- the only exception is for explicitly defined "build-only" routes which never match.
@@ -308,6 +320,37 @@ url, err := r.Get("article").URL("subdomain", "news",
                                  "id", "42")
 ```
 
+### Walking Routes
+
+The `Walk` function on `mux.Router` can be used to visit all of the routes that are registered on a router. For example,
+the following prints all of the registered routes:
+
+```go
+r := mux.NewRouter()
+r.HandleFunc("/", handler)
+r.HandleFunc("/products", handler).Methods("POST")
+r.HandleFunc("/articles", handler).Methods("GET")
+r.HandleFunc("/articles/{id}", handler).Methods("GET", "PUT")
+r.Walk(func(route *mux.Route, router *mux.Router, ancestors []*mux.Route) error {
+    t, err := route.GetPathTemplate()
+    if err != nil {
+        return err
+    }
+    // p will contain a regular expression that is compatible with regular expressions in Perl, Python, and other languages.
+    // For example, the regular expression for path '/articles/{id}' will be '^/articles/(?P<v0>[^/]+)$'.
+    p, err := route.GetPathRegexp()
+    if err != nil {
+        return err
+    }
+    m, err := route.GetMethods()
+    if err != nil {
+        return err
+    }
+    fmt.Println(strings.Join(m, ","), t, p)
+    return nil
+})
+```
+
 ## Full Example
 
 Here's a complete, runnable example of a small `mux` based server: