Racket binding to Named Data Networking

This forms part of the 7th ndn hackathon hosted by the NDN Consortium

Steps to Reproduce
$ git clone https://github.com/7th-ndn-hackathon/rkt-ndn
$ cd rkt-ndn/ndn-cpp-c-bindings
$ nix-build
$ ./result/bin/test-ndn-cpp-c-bindings 
epoch milliseconds: 1540153018518.364