Replacing bash ssh calls to the Net::SSH library.  

I tested this and it works.  This replaces all the `ssh ....` with net::ssh library.  I've run the whole test suite against this branch and everything passes.  
```ruby
def sshcmd(host = ENV['TESTHOST'], user = 'root', command)
  #Execute a command on the remote server
  #Not passing :password uses systems keys for auth
  out = StringIO.new
  err = StringIO.new
  Net::SSH.start(host, user) do |ssh|
    ssh.exec!(command) do |chan, str, data|
      out << data if str == :stdout
      err << data if str == :stderr
    end
  end
  if err.string.empty?
    { stdout: out.string, stderr: err.string }
  else
    raise "Execute command failed: #{command}: #{err.string}"
  end
end
```