Run tests for PRs

[ansd]

Run unit, integration, helm chart, and system tests tests.

Closes to #270

System tests run against a kind cluster on a GitHub hosted Ubuntu VM.

Why not running the system tests against GKE?

This would require to add a GitHub secret with the GCP key file for authentication: gcloud auth activate-service-account [ACCOUNT] --key-file=KEY_FILE.
This comes with two drawbacks:

1. PRs opened by forks won't be able to access this secret. Therefore, the action wouldn't be able to authenticate with GCP:

secrets are not passed to the runner when a workflow is triggered from a forked repository

see https://docs.github.com/en/actions/configuring-and-managing-workflows/creating-and-storing-encrypted-secrets

2. The key-file has JSON format. The same site states:

avoid creating secrets that contain JSON

When (accidentally) printing that JSON, the private key doesn't get redacted and would be accessible in the logs by every GitHub user:

2020-09-11T10:08:35.8906119Z   ***
2020-09-11T10:08:35.8907179Z   ***
2020-09-11T10:08:35.8907513Z   ***
2020-09-11T10:08:35.8907954Z   "private_key": "-----BEGIN PRIVATE KEY-----
2020-09-11T10:08:35.8908275Z aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
2020-09-11T10:08:35.8908597Z aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
2020-09-11T10:08:35.8908933Z aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
2020-09-11T10:08:35.8909238Z aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
2020-09-11T10:08:35.8909666Z aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
2020-09-11T10:08:35.8909985Z aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
2020-09-11T10:08:35.8910305Z aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
2020-09-11T10:08:35.8910636Z aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
2020-09-11T10:08:35.8910940Z aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
2020-09-11T10:08:35.8911249Z aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
2020-09-11T10:08:35.8911554Z aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
2020-09-11T10:08:35.8912259Z aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
2020-09-11T10:08:35.8912576Z aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
2020-09-11T10:08:35.8912890Z aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
2020-09-11T10:08:35.8913224Z aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
2020-09-11T10:08:35.8913541Z aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
2020-09-11T10:08:35.8913856Z aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
2020-09-11T10:08:35.8914175Z aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
2020-09-11T10:08:35.8914549Z aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
2020-09-11T10:08:35.8914858Z aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
2020-09-11T10:08:35.8915171Z aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
2020-09-11T10:08:35.8915522Z aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
2020-09-11T10:08:35.8915828Z aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
2020-09-11T10:08:35.8916138Z aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
2020-09-11T10:08:35.8916473Z aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
2020-09-11T10:08:35.8916771Z aaaaaaaaaaaaaaaaaaaaaaa=
2020-09-11T10:08:35.8917271Z -----END PRIVATE KEY-----
2020-09-11T10:08:35.8917549Z ",
2020-09-11T10:08:35.8918130Z   ***
2020-09-11T10:08:35.8918420Z   ***
2020-09-11T10:08:35.8918801Z   ***
2020-09-11T10:08:35.8919144Z   ***
2020-09-11T10:08:35.8919494Z   ***
2020-09-11T10:08:35.8920362Z   ***
2020-09-11T10:08:35.8920647Z ***

The solution in google-github-actions/setup-gcloud#134 to base64 encode the secret isn't convincing.

[Zerpet]

I'm going to add a WIP label to this PR based on #327 (comment). @ansd feel free to remove the label once you are happy with the state of the PR.