Implement e2e tests using k6

[pablochacin]

Presently the disruptor's e2e tests are implemented in go. These tests rely on a massive library developed in the project for

• Setting up a test cluster (using kind)
• Configuring the cluster (e.g. installing an ingress controller)
• Deploying the artifacts required for the test (pods, services, ingresses)
• Executing some actions and performing some validations

Maintaining this library in the project creates a considerable overhead. Therefore, it would be convenient to reuse existing tools in the k6 ecosystem:

• xk6-kubernetes for creating the test artifacts
• k6 for executing the test and performing validations

One task that seems to be outside the scope of these tools is the creation and configuration of the cluster itself, including:

• Exposing a port to access the kind cluster
• Install an ingress controller
• pre-load images needed by the tests (in particular, the disruptor's agent image that is built locally)

This task could be maintained in the project and potentially externalized as a separate tool.

k6-environment seems a promising candidate to help in this task.