As the Debian maintainer (where the current Ubuntu package originates),
my recommendation is biased ofcourse:
You can create a personal package archive on
launchpad.net, and upload
the current Ubuntu (or Debian) source package with an adapted
"distribution" field in debian/changelog ("unstable" --> "trusty"). It
will then build (hopefully) without major problems. Then you can include
the personal ppa into the travis-ci config.
Selfish addition: if you are very happy with that and want to have
others happy as well, you could then request a backport of the package:
https://wiki.ubuntu.com/UbuntuBackports
Best regards
Ole