Add Helm test for testing cert-manager-webhook-hetzner is working well

[mjtrangoni]

Hi @vadimkim,

After fixing #60, we should add a simple Helm Chart test. See here.

This way we can assure that the webhook is always 100% working.

1. It should be default disabled, so that this does not fail on users first installation.
2. We would need some test hetzner credentials available on this repository, for adding it to the CI

[vadimkim]

Thanks. Will read first. After merging #60 I can see that version is automatically incremented to 1.3.1, but tag shows 1.3.0.

[mjtrangoni]

@vadimkim I had to create a new version for this CI configuration, otherwise the helm test would fail. Note that app and helm are 2 separated things.

Anyways, you can still update both versions at the same time next time, ie. 1.3.2 or something like that.

The application version will be triggered by the git tag, but the helm package will be triggered by the Helm version in the Chart.yaml file.