[#73607174] Package locksmithctl version 0.1.8

Package `locksmithctl(1)`, a simple client to control a lock (or mutex) in an etcd backend, which we can use to control machine reboots to ensure only a specified number of machines is rebooted at any one time.

See also:
https://github.com/coreos/locksmith#usage

This build is for Trusty, but since it's a Go binary with almost no dependencies, we can use the same binary for Precise.
The repo actually has a `build` script in it. This is therefore deleting this script and replacing it with the directory in the build step, which isn't ideal.

Given this is only building `locksmithctl` form this repo, the build step could just be:
```sh
(cd locksmithctl && go build -o locksmithctl)
```
which woulc create the binary as `locksmithctl/locksmithctl`