add-regression-tests-for-discard (patch 1 of 1)

'git apply --summary --stat --apply --verbose' output was:

fatal: git apply: bad git-diff - expected /dev/null on line 4

For original context, see http://www.postgresql.org/message-id/CAEP4nAxs_sDKc7jG2-xFt-=os+_+cf-5wqcVc2kdyKrifH-YiQ@mail.gmail.com
Adding travis.yml