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.
Adds `-job` flag argument to `nomad fs` commands to randomly lookup a
job's allocation-id to use in an `fs` command.
Can be used when debugging a job, where a specific allocation ID is not
a strict requirement.
