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/pkcs12/errors.go

@@ -1,23 +0,0 @@
-// Copyright 2015 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.
-
-package pkcs12
-
-import "errors"
-
-var (
-	// ErrDecryption represents a failure to decrypt the input.
-	ErrDecryption = errors.New("pkcs12: decryption error, incorrect padding")
-
-	// ErrIncorrectPassword is returned when an incorrect password is detected.
-	// Usually, P12/PFX data is signed to be able to verify the password.
-	ErrIncorrectPassword = errors.New("pkcs12: decryption password incorrect")
-)
-
-// NotImplementedError indicates that the input is not currently supported.
-type NotImplementedError string
-
-func (e NotImplementedError) Error() string {
-	return "pkcs12: " + string(e)
-}