update all vendored dependencies

vendor/cloud.google.com/go/storage/doc.go

@@ -23,8 +23,6 @@ All of the methods of this package use exponential backoff to retry calls
 that fail with certain errors, as described in
 https://cloud.google.com/storage/docs/exponential-backoff.
 
-Note: This package is in beta.  Some backwards-incompatible changes may occur.
-
 
 Creating a Client
 
@@ -36,6 +34,13 @@ To start working with this package, create a client:
         // TODO: Handle error.
     }
 
+The client will use your default application credentials.
+
+If you only wish to access public data, you can create
+an unauthenticated client with
+
+    client, err := storage.NewClient(ctx, option.WithoutAuthentication())
+
 Buckets
 
 A Google Cloud Storage bucket is a collection of objects. To work with a