face: bugfix of MulticastUdpFace receiving packets from all available NICs on Linux

Now on Linux the creation of MulticastUdpFace requires
CAP_NET_RAW capability if the name of the interface is specified

Change-Id: Iff53035371fb26c6ee40e1065a0935e5ed16dc60
Refs: #1475
ci: Make travis-ci to run separated test cases

Change-Id: I78fa6fcdfbe3eda5b7c1fe5c063be9549d8185a7