Switch to using the dep tool and update all the dependencies

vendor/golang.org/x/crypto/ssh/test/doc.go

@@ -0,0 +1,7 @@
+// Copyright 2012 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// This package contains integration tests for the
+// golang.org/x/crypto/ssh package.
+package test // import "golang.org/x/crypto/ssh/test"