[ofiwg] Travis CI testing of libfabric and fabtests

[Hefty, Sean]

There are several github projects available that provide continuous integration testing.  Unless there is an objection, I plan on setting up Travis CI to test both libfabric and fabtests.  The current intent is just to see what we can do with it.  For example, verify the build, test that pull requests work with fabtests, look for regressions, etc.

- Sean