Add postgresql 9.3 addon to Travis CI configuration
Attempt to fix Travis CI build
Run apt-get update before Travis CI build
Merge remote-tracking branch 'upstream/master' into get-upstream-changes
Display error details when plpydbapi.Error is raised

This patch will show errors like:

InternalError: plpydbapi.Error: duplicate key value violates unique
constraint "files_pkey"

instead of:

InternalError: plpydbapi.Error: