make JSON output compatible with jq (for action:get among others)

[rabbah]

Is your feature request related to a problem? Please describe.
When you action:get, you get the action's name printed before the JSON API response.

> ./bin/run runtime:action:get foo
foo
 { ... }

This makes the output incompatible with jq to project some subset of the values of interest. Since aio here diverges from wsk's output of "ok: got action foo", perhaps do it better by dropping the action name that's currently prefixing the JSON response.

Describe the solution you'd like

> ./bin/run runtime:action:get foo
 {
  "annotations": [
    {
      "key": "exec",
      "value": "nodejs:10"
    }
  ],
  "exec": {
    "kind": "nodejs:10",
    "binary": false
  },
  "limits": {
    "concurrency": 1,
    "logs": 10,
    "memory": 256,
    "timeout": 60000
  },
  "name": "foo",
  "namespace": "guest",
  "parameters": [],
  "publish": false,
  "version": "0.0.1"
}

Describe alternatives you've considered
Wrap the cli with another bash script.

[adobe-bot]

JIRA issue created: https://jira.corp.adobe.com/browse/ACNA-587

[shazron]

Hints for the hackathon:

1. The action:get code is this nested file: https://github.com/adobe/aio-cli-plugin-runtime/blob/master/src/commands/runtime/action/get.js
2. The code that prints out that line is here:

   aio-cli-plugin-runtime/src/commands/runtime/action/get.js

   Line 74 in 2319ae9

   this.logJSON(`${result.name}\n`, { ...result,