Update notary vendor to 0.6.0

Signed-off-by: Justin Cormack <justin.cormack@docker.com>

vendor/github.com/theupdateframework/notary/client/client.go

@@ -1,88 +1,4 @@
-/*
-Package client implements everything required for interacting with a Notary repository.
-
-Usage
-
-Use this package by creating a new repository object and calling methods on it.
-
-	package main
-
-	import (
-		"encoding/hex"
-		"fmt"
-		"net/http"
-		"os"
-		"time"
-
-		"github.com/docker/distribution/registry/client/auth"
-		"github.com/docker/distribution/registry/client/auth/challenge"
-		"github.com/docker/distribution/registry/client/transport"
-		notary "github.com/theupdateframework/notary/client"
-		"github.com/theupdateframework/notary/trustpinning"
-		"github.com/theupdateframework/notary/tuf/data"
-	)
-
-	func main() {
-		rootDir := ".trust"
-		if err := os.MkdirAll(rootDir, 0700); err != nil {
-			panic(err)
-		}
-
-		server := "https://notary.docker.io"
-		image := "docker.io/library/alpine"
-		repo, err := notary.NewFileCachedNotaryRepository(
-			rootDir,
-			data.GUN(image),
-			server,
-			makeHubTransport(server, image),
-			nil,
-			trustpinning.TrustPinConfig{},
-		)
-
-		targets, err := repo.ListTargets()
-		if err != nil {
-			panic(err)
-		}
-
-		for _, tgt := range targets {
-			fmt.Printf("%s\t%s\n", tgt.Name, hex.EncodeToString(tgt.Hashes["sha256"]))
-		}
-	}
-
-	func makeHubTransport(server, image string) http.RoundTripper {
-		base := http.DefaultTransport
-		modifiers := []transport.RequestModifier{
-			transport.NewHeaderRequestModifier(http.Header{
-				"User-Agent": []string{"my-client"},
-			}),
-		}
-
-		authTransport := transport.NewTransport(base, modifiers...)
-		pingClient := &http.Client{
-			Transport: authTransport,
-			Timeout:   5 * time.Second,
-		}
-		req, err := http.NewRequest("GET", server+"/v2/", nil)
-		if err != nil {
-			panic(err)
-		}
-
-		challengeManager := challenge.NewSimpleManager()
-		resp, err := pingClient.Do(req)
-		if err != nil {
-			panic(err)
-		}
-		defer resp.Body.Close()
-		if err := challengeManager.AddResponse(resp); err != nil {
-			panic(err)
-		}
-		tokenHandler := auth.NewTokenHandler(base, nil, image, "pull")
-		modifiers = append(modifiers, auth.NewAuthorizer(challengeManager, tokenHandler, auth.NewBasicHandler(nil)))
-
-		return transport.NewTransport(base, modifiers...)
-	}
-
-*/
+//Package client implements everything required for interacting with a Notary repository.
 package client
 
 import (