https://github.com/heptiolabs/healthcheck

This will give us metric on healtcheck and more granularity on checks we want to have.

/cc @slim-bean @joe-elliott

On contexts with many APIs and APIs calling other APIs in chains, having too many spans in the zipkin/jaeger dashboards may lead to a too complex usage of such dashboards and of not necessary big data volumes.

For Tyk's admin team, the steps representing the time spent in each Tyk middleware are much valuable.

But the upstream APIs teams just want to know the global time spent in Tyk interna

What would you like to be added:
statefulset/cloneset/sidecarset/job need to add metric with replica, available, unavailable, complete, number of resource .....

Why is this needed:
For example, Deploy has kube-state-metric, which can provide the metric, so we can well count and monitor it in Prometheus. Kruise'

We should add events for every step of the application object state in Application controller.

Currently, the events is null when we use kubectl describe to see the application object.

$ kubectl describe application app-basic
Name:         app-basic
Namespace:    default
Labels:       <none>
Annotations:  <none>
API Version:  core.oam.dev/v1beta1
Kind:         Application
Metad

What happened:

pixiu is now v0.2.0 version, but the version field is still 0.1.0

**What you