display space id in status output

[murrayju]

This updates ghost status to display the space id.

> ghost status
Space: v3bksjls04
Compute: 101/200 hours (50.5%)
Storage: 147MiB/1TiB (0%)
Databases: 1 (1 running)

> ghost status --json
{
  "compute_minutes": 6060,
  "compute_limit_minutes": 12000,
  "storage_mib": 147,
  "storage_limit_mib": 1024000,
  "databases": {
    "running": 1
  },
  "cost_to_date": 0,
  "estimated_total_cost": 0,
  "billing_period_start": "1970-01-01T00:00:00Z",
  "billing_period_end": "1970-01-01T00:00:00Z",
  "space_id": "v3bksjls04"
}