Execution example::

  % groonga /tmp/groonga-databases/introduction.db
  status
  # [
  #   [
  #     0, 
  #     1337566253.89858, 
  #     0.000355720520019531
  #   ], 
  #   {
  #     "uptime": 0, 
  #     "max_command_version": 3, 
  #     "start_time": 1514346060, 
  #     "cache_hit_rate": 0.0, 
  #     "version": "7.0.9", 
  #     "alloc_count": 13365, 
  #     "command_version": 1, 
  #     "starttime": 1514346060, 
  #     "default_command_version": 1, 
  #     "n_queries": 0
  #   }
  # ]
