Move health concerns into separate package

[enocom]

• Rename gameservers.HealthController to health.Monitor
• Duplicate test helper code across packages

Fixed #88

[enocom]

One concern here is the duplication of test helper code. I'm tempted to leave it as is and revisit the issue once we find another concern to extract from the gameservers package.

[markmandel]

Apologies,

So this is far larger scope than what I was trying to suggest.

I just meant the the http health check server should be removed - not the backing code that watched Pods and moves back up to GameServers, as that is gameserver specific.

The original ticket was more because I felt like the http server should be started in the cmd/controller, rather than in the controller, and how we want to monitor overall controller health.

The logic to do the health status values on Pods -> GameServers I feel should stay where it was, as it's very specific to GameServers, and doesn't (at this stage) have impact outside of that.

Let me know if that doesn't make sense - sounds like we should have had more of a design discussion in #88

[enocom]

Sounds good. Let's continue the design discussion in the issue.

[agones-bot]

Build Succeeded 👏

Build Id: 31658259-c2b3-4258-9db5-617f8a7be3ea

The following development artifacts have been built, and will exist for the next 30 days:

• image: gcr.io/agones-images/agones-controller:0.1-76a1c52
• image: gcr.io/agones-images/agones-sdk:0.1-76a1c52
• Linux C++ Build (dev): agonessdk-0.1-76a1c52-dev-linux-arch_64.tar.gz
• Linux C++ Build (runtime): agonessdk-0.1-76a1c52-runtime-linux-arch_64.tar.gz
• SDK Server: agonessdk-server-0.1-76a1c52.zip