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/README.md

@@ -1,21 +0,0 @@
-# Go Cryptography
-
-This repository holds supplementary Go cryptography libraries.
-
-## Download/Install
-
-The easiest way to install is to run `go get -u golang.org/x/crypto/...`. You
-can also manually git clone the repository to `$GOPATH/src/golang.org/x/crypto`.
-
-## Report Issues / Send Patches
-
-This repository uses Gerrit for code changes. To learn how to submit changes to
-this repository, see https://golang.org/doc/contribute.html.
-
-The main issue tracker for the crypto repository is located at
-https://github.com/golang/go/issues. Prefix your issue with "x/crypto:" in the
-subject line, so it is easy to find.
-
-Note that contributions to the cryptography package receive additional scrutiny
-due to their sensitive nature. Patches may take longer than normal to receive
-feedback.