Add kustomize argument for kubectl

[yufeiminds]

Description

Fixes #915.

Kustomize is supported by kubectl -k official. I use this in my work, I think it may be useful for others.

Kubectl has an older version of Kustomize?

It is older than most recent version, but it is good enough for me. I don't want to install another tools.

TODOs

Read the Gruntwork contribution guidelines.

• Update the docs.
• Run the relevant tests successfully, including pre-commit checks.
• Ensure any 3rd party code adheres with our license policy or delete this line if its not applicable.
• Include release notes. If this PR is backward incompatible, include a migration guide.

Release Notes (draft)

Added Kustomize integration for k8s module.

Migration Guide

[denis256]

I think will be good if changes will have some basic tests to keep track over time if Kustomize functions will continue to work

[yufeiminds]

I think will be good if changes will have some basic tests to keep track over time if Kustomize functions will continue to work

Maybe I need your help to understand how to write and pass the test case in this repo. I have some questions:

1. Test check failed, but the logs are 404 not found.
2. Maybe I need a guide or example for contributors to understand how to run test cases locally without Github Actions.
3. I found two files (unit test, example test). I will write a test case as example test. Is it correct?

Terratest is an awesome project for infrastructure testing, I want to improve it better. Can you help me? @denis256 😄

[denis256]

Kubernetes tests passed without failures 👍