Convert gocardless/theatre to GitHub Actions

[sam-robson]

Pipeline migrated from Circle CI 🎉

Manual steps

Perform the follow steps to complete the migration:

gocardless/theatre/build-integration

• Ensure secret is available: ${{ secrets.CIRCLE_CI_SSH_KEY }}
• Ensure secret is available: ${{ secrets.CIRCLE_CI_KNOWN_HOSTS }}
• Ensure environment variable is updated: GITHUB_TOKEN

Raúl updated:

• Update go version to 1.19.3. Same that we had in circle.
• Webhooks are sent as POST requests, with Content-Type: application/json,
  with an AdmissionReview API object in the admission.k8s.io API group
  serialized to JSON as the body.

Webhooks can specify what versions of AdmissionReview objects they
accept with the admissionReviewVersions field in their configuration:

apiVersion: admissionregistration.k8s.io/v1
kind: ValidatingWebhookConfiguration
webhooks:
- name: foo.gocardless.com
  admissionReviewVersions: ["v1", "v1beta1"]

• actions/setup-go@4 enabled caching by default. That should speed up all the go dependencies.

Integration testing is failing

The following integration test is also failing:

Summarizing 4 Failures:

[Fail] Acceptance Consoles [It] Happy path 
/home/runner/work/theatre/theatre/cmd/workloads-manager/acceptance/acceptance.go:118

[Fail] Acceptance Consoles Runner interface [It] Happy path 
/home/runner/work/theatre/theatre/cmd/workloads-manager/acceptance/acceptance.go:242

[Fail] Acceptance Consoles [It] Deleting a console template 
/home/runner/work/theatre/theatre/cmd/workloads-manager/acceptance/acceptance.go:415

[Fail] Acceptance Consoles [It] Deleting a job 
/home/runner/work/theatre/theatre/cmd/workloads-manager/acceptance/acceptance.go:460

Ran 8 of 8 Specs in 16.624 seconds
FAIL! -- 4 Passed | 4 Failed | 0 Pending | 0 Skipped

I had runed this locally, and I consistently get similar errors. So I think it is best to get this change in and handle the acceptance tests in a following PR

• I haven't tested the release process, which refers to the variables that Sam mentioned here. However, at this point, we aren't going to a release; I can sort that out in a follow-up PR.

[rnaveiras]

See my comments in the PR