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 nfdc 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).