Changes to "ernest usage" output

[reidjc]

Example output:

"f1083f8c-4252-4dc7-586c-0762fdd5ffbb-aac44f07d84030d0341cc3afa436d8f3-public-3-instance": [
  {
    "id": 6,
    "service": "f1083f8c-4252-4dc7-586c-0762fdd5ffbb-aac44f07d84030d0341cc3afa436d8f3",
    "name": "public-3",
    "type": "instance",
    "from": "2017-04-19T10:44:17Z",
    "to": "0001-01-01T00:00:00Z"
  }

Requested changes:

1. "id" should be the ID listed in the output of the "history" command
2. "service" should be the NAME listed in the output of the "history" command
3. "to" should show either the deletion time for a deleted instance, or the command timestamp for an existing instance
4. add "group" field to show the group associated with the service