Fix mesh gateway example

[eeeschwartz]

(rehash of PR #7) This incorporates the central configs so that it works out of the box:

$ cd gateways
$ docker-compose up
$ curl localhost:9090
{
  "name": "web",
  "uri": "/",
  "type": "HTTP",
  "start_time": "2019-12-24T19:50:49.746164",
  "end_time": "2019-12-24T19:50:49.790219",
  "duration": "44.0532ms",
  "body": "Hello World",
  "upstream_calls": [
    {
      "name": "payments-v2",
      "uri": "http://localhost:9091",
      "type": "HTTP",
      "start_time": "2019-12-24T19:50:49.762915",
      "end_time": "2019-12-24T19:50:49.786688",
      "duration": "23.7739ms",
      "body": "PAYMENTS V2",
      "upstream_calls": [
        {
          "name": "currency-dc1",
          "uri": "http://localhost:9091",
          "type": "HTTP",
          "start_time": "2019-12-24T19:50:49.782486",
          "end_time": "2019-12-24T19:50:49.782897",
          "duration": "416.4µs",
          "body": "2 USD for 1 GBP",
          "code": 200
        }
      ],
      "code": 200
    }
  ],
  "code": 200
}

This also fixes a few broken images. If you prefer, I can submit without the whitespace changes.

Thanks for the demo. This is immensely helpful.

[nicholasjackson]

Oh wow thank you so much for the PR, I totally missed this @eeeschwartz .

Will merge first thing

[gc-ss]

Oh wow thank you so much for the PR, I totally missed this @eeeschwartz .

Will merge first thing

@nicholasjackson I am reading up on gateways and saw that this PR updates some of the gateways config - so are we good to merge this to master?