This patch adds a simple go benchmark test, injecting Kubernetes objects
and simulating scrape requests. It uses the Kubernetes client-go fake
client. Alongside comes some refactoring of each collectors structure
using informer factories to be compatible with the fake client.
The patch lays the groundwork to make future performance optimizations
comparable with past versions.
How to run test:
`go test -race -bench . -memprofile=mem.out -cpuprofile=cpu.out`
Max Leonard Inden