MulticastStrategy test scenario

Test Multicast Strategy

Steps:

1. Start NFD on A,B,C,D.
2. On host B,C, start ndn-traffic-server to serve ndn:/test-mcast.
3. On host A, invoke nfdc to set MulticastStrategy at ndn:/test-mcast.
4. On host A, invoke nfdc to create UDP tunnel to B, and add nexthop for ndn:/test-mcast to this face with cost 10.
5. On host A, invoke nfdc to create UDP tunnel to C, and add nexthop for ndn:/test-mcast to this face with cost 20.
6. On host D, invoke nfdc to create UDP tunnel to A, and add nexthop for ndn:/test-mcast to this face.
7. On host D, execute ndn-traffic-client to send 100 Interest to ndn:/test-mcast/A/<random>.
8. On host B,C, stop ndn-traffic-server. Fail if total served Interests on either host is less than 80.
9. On host D, invoke nfd-status to observe counters on the face created in step 6. Fail if total received Datas on this face is greater than 120 (because A should not forward the second copy of Data to D after PIT entry is satisfied).