Initial delivery of metrics code (#81)

* Initial delivery of metrics code

* Fix build issues

* Fix build issue with go vet

vendor/golang.org/x/crypto/blake2s/register.go

@@ -1,21 +0,0 @@
-// Copyright 2017 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.
-
-// +build go1.9
-
-package blake2s
-
-import (
-	"crypto"
-	"hash"
-)
-
-func init() {
-	newHash256 := func() hash.Hash {
-		h, _ := New256(nil)
-		return h
-	}
-
-	crypto.RegisterHash(crypto.BLAKE2s_256, newHash256)
-}