Add support for Caliper Push Gateway

[davidkel]

Caliper unstable and caliper4fabric fix the issue with push gateway. We should add support to enable push gateway. Note that the benchmarks will now need to include the following (although the rest of the dummy benchmark can still be blank)

monitors:
    transaction:
    - module: prometheus-push
      options:
        pushInterval: 500
        pushUrl: "http://localhost:9091"
        processMetricCollectInterval: 500

We will need to generate an appropriate dummy for workers replacing pushURL with the correct value.

Manager would need

• docker pull prom/pushgateway
• docker run -d -p 9091:9091 prom/pushgateway

need to update prometheus.yml

• job_name: pushgateway
  honor_labels: true
  static_configs:
  • targets: ['localhost:9091']