[Ndn-interest] go-ndn 1.2

[Tai-Lin Chu]

This release is not possible without some individual contributors.

Major Feature:

- experimental "send/push" semantics: A data sender sends interests
with name "<nodeName>/ACK/<dataName>" to ensure that a specific node
receives a specific data packet. This is implemented with
`mux.Notifier` and `mux.Listener`. Feel free to share how you achieve
send or push in NDN.

- go-ndn/health: instrument your ndn application easily. It stores
per-minute stats like interest request count and response time on
disk, and presents on a nice web interface. All web interface assets
are directly compiled into application and are available offline. (See
https://github.com/go-ndn/health)

Tutorial:

- Generate Data Before Interest: Discuss two common design patterns to
publish data "before" interests, and show how "self-generated/fake
interests" can achieve this.

https://github.com/go-ndn/example/blob/master/before-interest.md


Contributer:
- Oli Gavin
- qhsong
- Mahyuddin Husairi

More details: https://github.com/go-ndn/example#news