POC Run growth funnel verification specs in CI

Next step in the POC for running growth funnel verifications against snowplow micro.

This issue will take the next step where #428203 (closed) left off and focus on enabling the POC to run the tests in CI

Things to consider:

• starting the snowplow micro as a service(docker container)
  • Gitlab.config.host
• running this in its own job since it needs to run in serial as we only want to start one instance of snowplow micro initially.
  • maybe customize stub_application_setting(snowplow_app_id: 'gitlab-test') value to be something unique for an example.
    • Explore, but not vital, but this could get us away from clearing snowplow micro on each test and remove any parallel execution worries...or even need to create a separate job.
• may need to interface with engineering productivity team
• artifacts to be downloadable if it fails...pipe output to a file.