add extra verification test

defaults to listing jobs if no id is provided

This PR adds a version package and consolidates version strings into a
Version struct.

This PR removes our custom handling of the version flag and updates job
history to use a version flag instead of `-job-version`.

* Added the keygen command

* Added support for gossip encryption

* Changed the URL for keyring management

* Fixed the cli

* Added some tests

* Added tests for keyring operations

* Added a test for removal of keys

* Added some docs

* Fixed some docs

* Added general options

Refactors `nomad fs` command to eliminate `fs` subcommands.
Automatically displays the file, if the path specified is a file; lists
the directory if the path is a directory; or displays stat information
if the `-stat` flag is set.

Currently running `nomad fs ls` to find a file, then running the exact
same command with the exception of `cat` instead of `ls` is time
consuming and awkward. This allows operational testing to be greatly
enhanced, and makes our lives so much better.