Setup E2E tests using Newman

[geoffturk]

Postman offers a CLI tool called Newman to enable tests created in Postman to be run in a CI pipeline. Some background information here: https://javascript.plainenglish.io/postman-e2e-tests-integrated-into-github-actions-pipeline-with-newman-e800bb5e0235

• [x] Create a pre-commit git hook that runs Newman against the local/dev environment.

[geoffturk]

Newman CLI reference:
https://learning.postman.com/docs/running-collections/using-newman-cli/command-line-integration-with-newman/

Using pre-commit git hooks in Golang:
https://medium.com/@radlinskii/writing-the-pre-commit-git-hook-for-go-files-810f8d5f1c6f

[geoffturk]

Found this to preview changes before a PR is merged:
https://okteto.com/preview-environments/
https://okteto.com/docs/cloud/preview-environments/preview-environments-github/

Perhaps we could build a temporary K8s cluster to run the tests against, and then tear it down once the test run is completed.

[geoffturk]

Resolved by #207