Add integration tests

[dtuite]

This is a low functionality proof of concept. It uses GitHub actions to do the following:

1. Create a KinD k8s cluster in the Ubuntu box
2. Runs kubewise with go run main.go
3. Installs and uninstalls the zookeeper helm package.
4. Uploads the logs somewhere.

There is lots of scope for improvement

1. Assert that the output which is sent to Slack is correct. Currently, a manual visual inspection is required and I'm the only person who can see the Slack channel.
2. Perform an upgrade in the tests. Currently I'm just doing install and uninstall.

Lower priority improvements

1. Come up with a better way to background kubewise while giving it enough time to initialize before moving on with the helm commands. Currently I'm just using a sleep.
2. Make more build variables. For example, the helm package, repo and version to install could be variables.
3. Test the helm chart somehow. By using go run main.go I'm bypassing any problems which might happen in the chart.