Stop button

[lukeoguro]

Implements the edamame stop command, which will first search for a running test, and then stop any processes if a test is running.

Some notable changes:

• Changes the order of execution in phaseOutK6 — the k6 resource instance is deleted first to stop the test immediately before any other steps take place.
• Changes the order of execution in launchK6Test — the k6 resource instance is applied a bit earlier in the process so that tests can be stopped earlier in the edamame run process.

To test, execute edamame run and check to see that your Grafana dashboard is getting data. Then, execute edamame stop. Once it's finished, runkubectl get k6, kubectl get nodes, kubectl get pods to check that everything is phased out.

Note that the current implementation is not perfect — if the test is stopped immediately after a test launches, it won't be able to find a test and stop the process.

Resolves #60

[gcpinckert]

Works great for me!

Nice job!!