Wait for rollout status complete; abort on failure

[Ulexus]

Fixes #9

This is one way to achieve the desired goal. It's simple, but it has a few downsides:

• Serializes rollouts: only one rollout will occur at a time (this is arguable as to whether it is a downside)
• Does not roll back previous rollout if a subsequent rollout fails.

Of these, I consider the latter to be the more significant. It would be easy enough to track each rollout in the execution so they can be rolled back on failure, but since one of your TODOs is rewriting this as a Go-based plugin, having a real programming language would make that tracking much easier.

[MacTynow]

@Ulexus I haven't really gotten the time to re-write it yet, but you're right, I should be doing it especially since it will make testing easier. I should have some time soon.

Regarding the PR, please look at my comment. This would probably be a breaking change for us if we exit when the rollout status is not 0.

[so0k]

@Ulexus in offline discussion @MacTynow suggested adding an abort_on_failure option, default to false? This way it doesn't change the behaviour of the plugin for people using it already and it gives control to the user.

Would that be a good middle ground?

[Ulexus]

That sounds perfectly reasonable to me. I'll see if I can scrounge the time this week to implement that.

[so0k]

@MacTynow - are you able to comment here yet, I added you as an outside collaborator

Honestbee has fully moved to use helm for release management