Metric logger

[Thomasdezeeuw]

Add metrics function, something like:

func CollectMetrics(every time.Duration) {
  // collecting...
}

[Thomasdezeeuw]

By default track stuff like:

• cpu usage (application or al?)
• memory usage (application or all?)
• disk usage (application or all?)?

Add custom counter with for example number of active requests and total number of request processed.