Implement CI for helm chart

[kolikons]

Added CI github action for cheking syntax helm charts

• https://github.com/helm/chart-testing

Important:
If you made some changes in dependency chart. You have to perfrom to build Chart.lock file before you push commit into repo

helm dependency build policy-reporter
or
helm dependency update policy-reporter

tests:

 ct lint --lint-conf=.github/ct_lintconf.yaml --chart-yaml-schema=.github/ct_chart_schema.yaml --validate-maintainers=false   --target-branch=main --chart-dirs charts
Linting charts...

------------------------------------------------------------------------------------------------------------------------
 Charts to be processed:
------------------------------------------------------------------------------------------------------------------------
 policy-reporter => (version: "0.17.1", path: "charts/policy-reporter")
------------------------------------------------------------------------------------------------------------------------

Hang tight while we grab the latest from your chart repositories...
Update Complete. ⎈Happy Helming!⎈
Saving 2 charts
Dependency monitoring did not declare a repository. Assuming it exists in the charts directory
Dependency policy-reporter-ui did not declare a repository. Assuming it exists in the charts directory
Deleting outdated charts
Linting chart 'policy-reporter => (version: "0.17.1", path: "charts/policy-reporter")'
Checking chart 'policy-reporter => (version: "0.17.1", path: "charts/policy-reporter")' for a version bump...
Old chart version: 0.17.0
New chart version: 0.17.1
Chart version ok.
Validating /github/policy-reporter/charts/policy-reporter/Chart.yaml...
Validation success! 👍
==> Linting charts/policy-reporter
[INFO] Chart.yaml: icon is recommended

1 chart(s) linted, 0 chart(s) failed
------------------------------------------------------------------------------------------------------------------------
 ✔︎ policy-reporter => (version: "0.17.1", path: "charts/policy-reporter")
------------------------------------------------------------------------------------------------------------------------
All charts linted successfully

FYI: if you want to implement e2e test, you can create use for example: https://github.com/helm/chart-testing/tree/master/examples/kind

[kolikons]

https://github.com/fjogeleit/policy-reporter/pull/15/checks?check_run_id=2126524644

[fjogeleit]

Great improvement, thanks a lot! I will have a look on the e2e stuff.