Multicast test scenario

Test UDP and Ethernet multicast faces.

1. Start NFD on A, B, and C.
2. On host A, insert FIB entry ndn:/test-mcast to either UDP or Ethernet multicast face on experiment NIC.
3. On host B, start traffic generator producer to serve ndn:/test-mcast/B, ndn:/test-mcast/Z.
4. On host C, start traffic generator producer to serve ndn:/test-mcast/C, ndn:/test-mcast/Z.
5. On host A, invoke ndnpeek ndn:/test-mcast/B/1. Fail the test if this Interest is unanswered.
6. On host A, invoke ndnpeek ndn:/test-mcast/C/1. Fail the test if this Interest is unanswered.
7. On host A, invoke ndnpeek ndn:/test-mcast/Z/1. Fail the test if this Interest is unanswered.
8. On host B, kill the producer.
9. On host A, invoke ndnpeek ndn:/test-mcast/Z/2. Fail the test if this Interest is unanswered.