* Update zipkin, etcd, klog and aws

This fix updates:
- github.com/openzipkin/zipkin-go-opentracing
- k8s.io/klog
- github.com/coreos/etcd
- github.com/aws/aws-sdk-go

This fix fixes #2906
This fix fixes #2907
This fix fixes #2908
This fix fixes #2909
Signed-off-by: Yong Tang <yong.tang.github@outlook.com>

* Also updates opentracing
Signed-off-by: Yong Tang <yong.tang.github@outlook.com>