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/chacha20poly1305/chacha20poly1305_noasm.go

@@ -1,15 +0,0 @@
-// Copyright 2016 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 !amd64 !go1.7 gccgo appengine
-
-package chacha20poly1305
-
-func (c *chacha20poly1305) seal(dst, nonce, plaintext, additionalData []byte) []byte {
-	return c.sealGeneric(dst, nonce, plaintext, additionalData)
-}
-
-func (c *chacha20poly1305) open(dst, nonce, ciphertext, additionalData []byte) ([]byte, error) {
-	return c.openGeneric(dst, nonce, ciphertext, additionalData)
-}