Fix travis build errors

I was able to reproduce this error again, on my workstation.  After turning up the debugging to 11 I noticed that I was seeing an error loading Socket.so from my perlbrew'd perl by the system perl.  I am not sure why pg_dump should need perl or be using PERL5LIB, but this seems to do the trick.

I also added 5.12 to the travis test, since that is what we are using here, and made the test step more verbose and thus easier to debug.