Add chart-testing via github actions

[bdashrad]

Test the privatebin-helm chart the same way the core helm charts are tested.

I'd like to think about moving to github actions for deploying the helm repo to github pages as well.

[elrido]

Makes sense to keep it all in one place. If I understand Github actions and our TravisCI setup correctly, you would need to replicate the below into a ruby based Github action?

helm-chart/.travis.yml

Lines 1 to 19 in cbdf928

	---
	language: ruby
	before_install:
	- curl https://raw.githubusercontent.com/kubernetes/helm/master/scripts/get > get_helm.sh
	- sudo bash ./get_helm.sh
	- helm version --client
	- helm init --client-only
	script:
	- rake package
	- rake clone
	- rake index
	deploy:
	- provider: pages
	skip_cleanup: true
	github_token: $GITHUB_TOKEN
	keep_history: true
	local_dir: docs
	on:
	branch: master

Like this one, maybe? https://github.com/helm/chart-releaser-action

[bdashrad]

@elrido Yes, i'm looking to use the chart-releaser-action to replace our current setup. I need to research migrating the existing content to make sure we don't lose any historical versions (in case they are in use). I'm hoping to get to it over the weekend. For now I wanted to add the chart-testing since I switched to it on some work projects and it's working well.

[bdashrad]

@elrido how do you feel about getting this merged before we migrate the chart releaser part, to catch things like version change requirements as we update the chart?

[elrido]

Yes, lets set this up!