Add support for Vagrant

[martint17r]

Description

Use the Vagrantfile to create a workable test machine in a few minutes
to run the unit and most of the integration tests on non-Linux systems.

I tried to contribute to kaniko but did not manage to make the tests pass on macOS (as there is no /proc mount). I first tried to create a Dockerfile, but the integration tests won't run with Docker Desktop because they can't mount the workspace for kaniko when building the images. After that I converted the Dockerfile to Vagrant

The integration tests pass individually, but the kubernetes stuff fails. I failed to find documentation on how to set that up. If you give me a pointer I would be happy to add kind or find another way to run them as well.

Submitter Checklist

These are the criteria that every PR should meet, please check them off as you
review them:

• [n/a] Includes unit tests
• [n/a] Adds integration tests if needed.

See the contribution guide for more details.

Reviewer Notes

• The code flow looks good.
• Unit tests and or integration tests added.